I hope you enjoy the course :) And check out Tabnine, the FREE AI-powered code completion tool that helps you to code faster: www.tabnine.com/?.com&PythonEngineer * ---------------------------------------------------------------------------------------------------------- * This is a sponsored link. You will not have any additional costs, instead you will support me and my project. Thank you so much for the support! 🙏
at 37:00 I found after adding 2 that not all members of the tensor had exactly x+2. I tried this several times with always one of the parts of the tensor had less than x+2. Then at 37:16 you also had an anomaly. Why is this?
Incredible tutorial, thank you! Some corrections: - 1:12:02 correct gradient function in the manual gradient calculation should be `np.dot(2*x, y_predicted - y) / len(x)`, because np.dot results in a scalar and mean() has no effect of calculating the mean. (TY @Arman Seyed-Ahmadi) - 1:23:52 the optimizer is applying the gradient exactly like we do, there is no difference. The reason the PyTorch model has different predictions is because 1) you use a model with a bias, 2) the values are initialized randomly. To turn off the bias use `bias=False` in the model construction. To initialize the weight to zero use a `with torch.no_grad()` block and set `model.weight[0,0] = 0`. Then all versions result in the exact same model with the exact same predictions (as expected).
Thanks for this second comment! To add to this: nn.Linear wants to solve y = wx + b here. This 'b' is the bias, and by setting bias = False, instead it learns y = wx as we want it to. This also means that model.parameters() will yield only [w] and not [w, b] anymore, so do not forget to change that in line 52 in the video as well.
This is one of the very few videos which is teaching Pytorch from the ground up! Beautiful work, @Python Engineer. Highly recommend it for any newbie + refresher.
This is a fantastic tutorial, thank you for sharing this great material! There is one mistake though that needs clarification: ========================================== At 1:12:02 it is mentioned that the code with automatic differentiation does not converge as fast because "back-propagation is not as exact as the numerical gradient". This is incorrect: the reason why the convergence of the two codes are different is because there is a mistake in the gradient() function. When the dot product np.dot(2x, y_pred_y) is performed, the result is a scalar and .mean() does not do anything. Instead of doing .mean(), np.dot(2x, y_pred_y) should simply be divided by len(x) to give the correct mean gradient. After doing this, both methods give the exact same convergence history and final results.
Thanks for the course Patrick! It was a great refresher! BTW, at 3:42:02, in the newer versions instead of pretrained=True it is changed to weights=True.
For the feedforward part, you need to send the model to the GPU when instantiating it: model = NeuralNet(input_size, hidden_size, num_classes).to(device) if your device is 'cuda' and you forget the '.to(device)' you will get an error.
I just completed the course on ML from scratch from Python Engineer. It was a great course for someone who learned all those algorithms in the past and wants to see how they get implemented using basic python lib and numpy.
Thanks a lot for the low level explanations. At 1:01:47 when you dot product the array turns into a single scalar. So mean() returns that number(the sum), not average. When you fix it you get the exact same results as with pytorch's implementation in 1:12:00
@@phi6934 I don't remember the details right now, but just dividing the expression with the size of the tensor must do the work. In the expression put smt like .../len(x) instead of .mean()
On 4:14:00, I think you should use the ground truth as the labels rather than the predicted (line 130). Because the PR curve use the ground truth and predicted score to paint
at 1:01:41 he uses np.dot and when it should be np.multiply, that will make it consistent with the pytorch implementation. By doing np.dot, the items are multiplied and summed leaving just one value to which the mean function is applied, so the reason the numpy version get to 0 loss quicker is the gradient is not being averaged correctly.
Thanks for the awesome course! The material is extremely well curated, every minute is pure gold. I particularly liked the fact that for each subject there is a smooth transition from numpy to torch. It's perfect for someone who wants a quick and thorough deeplearning recap and get comfortable with hands-on pytorch coding.
This is the best course on this topic I've seen so far. It is perfect when you want to understand what you're doing and the way things are brought is very pedagogic.
Your course is great! Congratulations! I just had to do a small correction in your code in part "13. Feed Forward Net" so that I could run it on GPU. It was necessary to add the "device" (that was preciously declared) as an argument in the nn.Linear function. Without this detail it is not possible to run the code in GPU. class NeuralNet(nn.Module): def __init__(self, input_size, hidden_size, n_classes, device): super(NeuralNet,self).__init__() self.l1 = nn.Linear(input_size, hidden_size, device=device) self.relu = nn.ReLU() self.l2 = nn.Linear(hidden_size, n_classes, device=device) def forward(self, x): out = self.l1(x) out = self.relu(out) out = self.l2(out) return out
If z is a scalar then z.backward() is defined (and I understand the computation), while if z is not a scalar then z.backward() is not defined unless you provide appropriate inputs. However, it was not entirely clear to me what computation is occurring when we do z.backward(x) for example (where x is appropriate). This subject matter is around 33:00.
What is happening is that PyTorch is assuming that you have provided the intermediate gradients i.e. (dLoss/dz), then using these intermediate gradients PyTorch is able to compute the gradients further downstream and backward step is successful.
Nice tutorial ! @1:11:40 at line # 37. Instead of using "w -= learning_rate * w.grad" , I used expanded form "w = w - learning_rate * w.grad" and thought it would be same. But in this case 'w.grad' return 'None'. w.require_grad is False and hence error. Though "w -= learning_rate * w.grad" is same as "w.data = w.data - learning_rate * w.grad". It seems torch Tensor ( with require_grad True) have some overridden "__iadd__" implementation.
In the Gradient Descent and Training Pipeline sections, the presenter glosses over why it takes 5x more training steps to converge. There are a couple factors: - Autograd is less aggressive than the manual gradient calculation, effectively lowering the learning rate (you can go all the way up to 0.1 after you move to torch and autograd) - nn.Linear() includes a bias by default and a non-zero initialization of the weights, making it not a direct comparison. You can get much closer by adding `bias=False` to the model initialization and by zeroing out the weigth with `model.weight.data.fill_(0.0`
Dear with apologies kindly notice, At timestamp 1:12:05 make a correction in stating, that the backprop grad was not correct, Actually the numerical one was not correct. Because np.dot is computing a single number and then taking mean is the same number, instead use 2*x/4 in np.dot(2*x,(Y_pred-Y).mean()) to correct your numerical gradient. Using np.dot(2*x/4,(Y_pred-Y)) will produce same result as back propagated result. Mean will be usefull when W and X are matrices. Thank you
1:12:09 It's because the gradient in your formula is not correct, not because pytorch's backpropogation calculation. You should put the ".mean()" into the brackets of "np.dot()".
Excellent series. Using this to review what I've learned and to also learn PyTorch, thank you for this. The only thing I'd change is that you add an upward inflection to the end of most of your sentences which is a bit jarring (makes it sound like every sentence is a question).
I've taken a graduate course in deep learning and neural, and have watched other tutorials here and there, but this is by far the most helpful one. Granted, all the previous materials have probably contributed, but the way you teach is unparalleled!
Great tutorial! one small point regarding CNN - CIFAR10 While calculation accuracy , its better to use for i in range(len(labels)): than for i in range(len(lbatch_size)): since if last set of batch_size less than original batch_size given then it will throw index bound error
This tutorial is supppppppppppper great! The best deep learning tutorial I've ever watched. Thank you so much. I enjoined the tutorial that I didn't want it to stop! I look forward to seeing more great videos like this from this channel
a probable mistake: Leaky ReLU isn't used for solving the problem of vanishing gradient problem but Dead Neurons problem. Which can happen when you use ReLU activation functions.
Someone has probably mentioned this already, but on line 23 at 1:04:08 .mean() is not doing anything since taking the dot product already returned a scalar. This is just dividing by one. Instead, you should be dividing by len(x) or len(y), or there may be another more efficient way to get the same result.
Wow. This course is awesome. An end to end of everything. I was wondering why I need to learn about Tensorboard and JSON files (other series) for using Torch. This was very useful to me.
Absolutely great. But what was missing for me was how then to use a trained model. Conspicuous in its absence was how at the end to feed data into a trained model and get the answer it was trained to give. Is there another video that explains this?
Great stuff but really frustrating that people do not do object detection tutorials for PyTorch especially for Tensorboard. I have trained a really good object detection system on pytorch for jetson nano however implementing tesnorboard into the trainer it has been difficult to find information on drawing images to tensorboard with original groundtruth image side by side with predicted boxes and labels, so that you have a history on tensorboard throughout the steps to scroll and see how the detection validation set was performing. This is so important when doing large data sets and tens of hours of training! If you can point me in the right direction for this info would be very grateful!
Great tutorial on the tensorboard part. But you made a mistake when plotting the precision and recall curve when you append predicted into the labels where it should have been labels1 - the actual labels of the eval batch
This is an error I have found Time: 1:01:55 According to the equation,we actually need to find 1/N ,where N represents the number of term(here 4).According to the code,we are computing mean after converting the rest of the code to a dot product,which contains just a value.So instead of dividing with the desired value(4),we are dividing with 1.
Thanks for this incredible resource. FYI I believe the gradient function computed at 1:01:38 is incorrect. I'm pretty sure it should be: def gradient(x, y, y_predicted): return ((y_predicted-y)*2*x).mean()
![Build Your First Pytorch Model In Minutes! [Tutorial + Code]](http://i.ytimg.com/vi/tHL5STNJKag/mqdefault.jpg)
I hope you enjoy the course :)
And check out Tabnine, the FREE AI-powered code completion tool that helps you to code faster: www.tabnine.com/?.com&PythonEngineer *
----------------------------------------------------------------------------------------------------------
* This is a sponsored link. You will not have any additional costs, instead you will support me and my project. Thank you so much for the support! 🙏
at 37:00 I found after adding 2 that not all members of the tensor had exactly x+2. I tried this several times with always one of the parts of the tensor had less than x+2. Then at 37:16 you also had an anomaly. Why is this?
Thank you very much. You did a great work!
.👆Never love anyone who treats you like you’re ordinary.
great video! thank you but please don't delete each line that you code! wait till the subject is finished then delete them once
I’m really enjoying it mate. Hope you are doing well. 🎉
Incredible tutorial, thank you! Some corrections:
- 1:12:02 correct gradient function in the manual gradient calculation should be `np.dot(2*x, y_predicted - y) / len(x)`, because np.dot results in a scalar and mean() has no effect of calculating the mean. (TY @Arman Seyed-Ahmadi)
- 1:23:52 the optimizer is applying the gradient exactly like we do, there is no difference. The reason the PyTorch model has different predictions is because 1) you use a model with a bias, 2) the values are initialized randomly. To turn off the bias use `bias=False` in the model construction. To initialize the weight to zero use a `with torch.no_grad()` block and set `model.weight[0,0] = 0`. Then all versions result in the exact same model with the exact same predictions (as expected).
Thanks for this second comment! To add to this: nn.Linear wants to solve y = wx + b here. This 'b' is the bias, and by setting bias = False, instead it learns y = wx as we want it to. This also means that model.parameters() will yield only [w] and not [w, b] anymore, so do not forget to change that in line 52 in the video as well.
This is one of the very few videos which is teaching Pytorch from the ground up! Beautiful work, @Python Engineer. Highly recommend it for any newbie + refresher.
This is a fantastic tutorial, thank you for sharing this great material!
There is one mistake though that needs clarification:
==========================================
At 1:12:02 it is mentioned that the code with automatic differentiation does not converge as fast because "back-propagation is not as exact as the numerical gradient". This is incorrect: the reason why the convergence of the two codes are different is because there is a mistake in the gradient() function. When the dot product np.dot(2x, y_pred_y) is performed, the result is a scalar and .mean() does not do anything. Instead of doing .mean(), np.dot(2x, y_pred_y) should simply be divided by len(x) to give the correct mean gradient. After doing this, both methods give the exact same convergence history and final results.
I wishhhh saw your comment earlier. I was just going crazy that what am I doing wrong when calculating manually.
Thanks for this comment, I was a bit concerned when he said that.
Thanks for the course Patrick! It was a great refresher!
BTW, at 3:42:02, in the newer versions instead of pretrained=True it is changed to weights=True.
Wow this is so cool Patrick, a free course on PyTorch, great value you are bringing to the community 😆
Thanks so much :)
For the feedforward part, you need to send the model to the GPU when instantiating it:
model = NeuralNet(input_size, hidden_size, num_classes).to(device)
if your device is 'cuda' and you forget the '.to(device)' you will get an error.
omg thank you so much for this. saved me hours trying to figure out what was wrong serious life savor
This is literally incredible. Perfect mix of theory and actual implementation. I can't thank you enough
.👆Girls dream of chatting with you
I just completed the course on ML from scratch from Python Engineer. It was a great course for someone who learned all those algorithms in the past and wants to see how they get implemented using basic python lib and numpy.
Thanks a lot for the low level explanations.
At 1:01:47 when you dot product the array turns into a single scalar. So mean() returns that number(the sum), not average.
When you fix it you get the exact same results as with pytorch's implementation in 1:12:00
What is the correct expression of the gradient that gives the same result?
@@phi6934 I don't remember the details right now, but just dividing the expression with the size of the tensor must do the work. In the expression put smt like .../len(x) instead of .mean()
@@emrek1 yup that works thanks
I found that problem too, Thanks bro!
On 4:14:00, I think you should use the ground truth as the labels rather than the predicted (line 130). Because the PR curve use the ground truth and predicted score to paint
The best Pytorch tutorial online, I love how you explained the concepts using simple example and built on each concept one step at a time
Finally PyTorch doesnt seem as scary as it was before. The best tutorial I could find out there and I understood everything you've said. Thanks a lot.
glad to hear that :)
This is probably one of the best tutorials I've ever seen for pytorch. Thank you so much.
Thanks a lot! Glad you enjoy the course
I don't even need to watch it to know its quality. Can't wait to watch it and thanks for uploading!
Thanks! Hope you like it
at 1:01:41 he uses np.dot and when it should be np.multiply, that will make it consistent with the pytorch implementation. By doing np.dot, the items are multiplied and summed leaving just one value to which the mean function is applied, so the reason the numpy version get to 0 loss quicker is the gradient is not being averaged correctly.
thanks for pointing this out!
Thanks for the awesome course! The material is extremely well curated, every minute is pure gold. I particularly liked the fact that for each subject there is a smooth transition from numpy to torch. It's perfect for someone who wants a quick and thorough deeplearning recap and get comfortable with hands-on pytorch coding.
Best pytorch video tutorial I have found on entire internet. Also the codes are published. Just awesome
thanks a lot :)
When you explained backprop, I felt like I finally saw the light at an endless tunnel
hehe, happy to hear that!
This is the best course on this topic I've seen so far. It is perfect when you want to understand what you're doing and the way things are brought is very pedagogic.
The best hands-on tutorial on PyTorch on TH-cam! Thank you!
Your course is great! Congratulations!
I just had to do a small correction in your code in part "13. Feed Forward Net" so that I could run it on GPU. It was necessary to add the "device" (that was preciously declared) as an argument in the nn.Linear function. Without this detail it is not possible to run the code in GPU.
class NeuralNet(nn.Module):
def __init__(self, input_size, hidden_size, n_classes, device):
super(NeuralNet,self).__init__()
self.l1 = nn.Linear(input_size, hidden_size, device=device)
self.relu = nn.ReLU()
self.l2 = nn.Linear(hidden_size, n_classes, device=device)
def forward(self, x):
out = self.l1(x)
out = self.relu(out)
out = self.l2(out)
return out
Merci Beaucoup
by FAR the best, most complete and comprehensible tutorial for pytorch I've come across
The man the myth the LEGEND returns with the best video of all time. 💪🏻
GREAT JOB and THANK YOU! ❤️
Thank you :)
If z is a scalar then z.backward() is defined (and I understand the computation), while if z is not a scalar then z.backward() is not defined unless you provide appropriate inputs. However, it was not entirely clear to me what computation is occurring when we do z.backward(x) for example (where x is appropriate). This subject matter is around 33:00.
Same happened with me
What is happening is that PyTorch is assuming that you have provided the intermediate gradients i.e. (dLoss/dz), then using these intermediate gradients PyTorch is able to compute the gradients further downstream and backward step is successful.
Ten-soooor and Inter-ference are the best of the class!
This TH-cam video is the best tutorial for pytorch out there.Thankyou so much!
Wow, thanks!
Nice tutorial !
@1:11:40 at line # 37. Instead of using "w -= learning_rate * w.grad" , I used expanded form "w = w - learning_rate * w.grad" and thought it would be same. But in this case 'w.grad' return 'None'. w.require_grad is False and hence error.
Though "w -= learning_rate * w.grad" is same as "w.data = w.data - learning_rate * w.grad".
It seems torch Tensor ( with require_grad True) have some overridden "__iadd__" implementation.
unsupported operand type(s) for *: 'float' and 'builtin_function_or_method' got this error on that line. any help please
Came for pytorch, stayed for the accent!
TENZSOoooOR 😎
haha :D
OMG, you are an amazing teacher! Finally, I can grasp PyTorch and start building stuff. thank you so much
In the Gradient Descent and Training Pipeline sections, the presenter glosses over why it takes 5x more training steps to converge. There are a couple factors:
- Autograd is less aggressive than the manual gradient calculation, effectively lowering the learning rate (you can go all the way up to 0.1 after you move to torch and autograd)
- nn.Linear() includes a bias by default and a non-zero initialization of the weights, making it not a direct comparison. You can get much closer by adding `bias=False` to the model initialization and by zeroing out the weigth with `model.weight.data.fill_(0.0`
One of the best PyTorch tutorial series on TH-cam :)
the most useful video I have ever watched
happy to hear that!
this video was super helpful and clear, I watched everything up until transfer learning, ty so much
The best PyTorch tutorials I've ever watched.
Patrick, you're a legend. Thank you so much for this tutorial. Now on to more advanced stuff!
thanks a lot!
I have just finished the whole tutorial as a refresher. Everything is so much clearer now. Thanks.
Thanks a lot, this tutorial helped me tremendously with my bachelors thesis
Basic operations we can do, so x and y equals torch. so let's print x and y. So we do simple addition for example
Dear with apologies kindly notice, At timestamp 1:12:05 make a correction in stating, that the backprop grad was not correct, Actually the numerical one was not correct. Because np.dot is computing a single number and then taking mean is the same number, instead use 2*x/4 in np.dot(2*x,(Y_pred-Y).mean()) to correct your numerical gradient. Using np.dot(2*x/4,(Y_pred-Y)) will produce same result as back propagated result. Mean will be usefull when W and X are matrices.
Thank you
Thank you Python Engineer! This is the best tutorial video I've ever seen about pytorch.
This vid quality is ridiculously high, THANK YOU
This is the best Pytorch tutorial ever, thanks you!
This is amazing! It was fun to follow along and I feel like I am able to try pytorch on some projects now. Thank you 😍
2:59:00 -> Starting with PyTorch 1.13 examples.next() is no longer valid.
New syntax is: next(examples)
unbelievably excellent free tutorial course! Thank you!
Glad it was helpful!
Best tutorial on pytorch I've come across.
I followed all courses and this helps me a lot. Thanks a ton
Such a clear and comprehensive tut for Pytorch!
glad you like it :)
Here's the best channel for data science and ML
If you guys get an error on GPU at around 3:13:50, saying there is two devices, make sure you do model.to(device)
basic explanation about autograd was great
41:01 Please change torch.optim.SGD(weights,lr=0.01) to torch.optim.SGD([weights],lr=0.01), here wights are passed as array
1:12:09 It's because the gradient in your formula is not correct, not because pytorch's backpropogation calculation. You should put the ".mean()" into the brackets of "np.dot()".
Thank you very much, this tutorial it's super useful and it's making my life better!
Right! It's not the backward that isn't precise as he said, if you compute by hand it is indeed -30.
Correct. The np.dot() didn't actually get the mean (but the sum). Hence the gradient is larger than the true value and the convergence is faster.
Excellent series. Using this to review what I've learned and to also learn PyTorch, thank you for this. The only thing I'd change is that you add an upward inflection to the end of most of your sentences which is a bit jarring (makes it sound like every sentence is a question).
Thanks for the tips!
I've taken a graduate course in deep learning and neural, and have watched other tutorials here and there, but this is by far the most helpful one. Granted, all the previous materials have probably contributed, but the way you teach is unparalleled!
thank you so much! glad you like it :)
thank u for your patience!
This is the best tutorial on PyTorch
Perfect tutorial for a beginner!!!!!!!!
Glad you think so!
Cool, really a very nice course, thanks for your effort to make it free online!!!
Glad you enjoyed it!
Great tutorial! one small point regarding CNN - CIFAR10
While calculation accuracy , its better to use
for i in range(len(labels)):
than
for i in range(len(lbatch_size)):
since if last set of batch_size less than original batch_size given then it will throw index bound error
Amazing and Comprehensive coverage of PyTorch. Amazing Video. Thanks a lot
The only problem with this 4.5-hour video is that it does not provide me with a convenient way to like 17 times. Thanks for the series of tutorials!
Haha thank you!
This tutorial is supppppppppppper great! The best deep learning tutorial I've ever watched. Thank you so much.
I enjoined the tutorial that I didn't want it to stop!
I look forward to seeing more great videos like this from this channel
Awesome, thank you!
Well done, a very smooth intro to PyTorch.
Glad you like it!
Best course on pyTorch tutorial, thanks!
a probable mistake: Leaky ReLU isn't used for solving the problem of vanishing gradient problem but Dead Neurons problem. Which can happen when you use ReLU activation functions.
best pytorch tutorial ever
Someone has probably mentioned this already, but on line 23 at 1:04:08 .mean() is not doing anything since taking the dot product already returned a scalar. This is just dividing by one. Instead, you should be dividing by len(x) or len(y), or there may be another more efficient way to get the same result.
Man this is pure gold, thank you so much!
Wow. This course is awesome. An end to end of everything.
I was wondering why I need to learn about Tensorboard and JSON files (other series) for using Torch. This was very useful to me.
This is just great Patrick, thank you very much! How can I support you more?
Thank you so much, if I got a job by watching this, I want to make a donation.
I finished the whole video, again, thank you so much!
Awesome 💪🔥🚀
Thanks :)
Absoulte top quality videos! Thank you very much and may you go on forever
Absolutely great. But what was missing for me was how then to use a trained model. Conspicuous in its absence was how at the end to feed data into a trained model and get the answer it was trained to give. Is there another video that explains this?
Thanks for Ur help I'm able to learn many new things . Keep up this work .
Thank you
Glad to hear that!
fantastic video brother :D have great success
Really nice, well explained, well tested, etc.. Thanks a lot!!
Finished the tutorial love it
Before watching this I am a boy, after that I am a man. Thank you so much!
Great stuff but really frustrating that people do not do object detection tutorials for PyTorch especially for Tensorboard. I have trained a really good object detection system on pytorch for jetson nano however implementing tesnorboard into the trainer it has been difficult to find information on drawing images to tensorboard with original groundtruth image side by side with predicted boxes and labels, so that you have a history on tensorboard throughout the steps to scroll and see how the detection validation set was performing. This is so important when doing large data sets and tens of hours of training!
If you can point me in the right direction for this info would be very grateful!
thanks for the feedback. yes i haven't done object detection yet. but I'm planning to. I also have a jetson nano here :)
Great course, as always!
thanks, awsome introduction to Pytorch
happy to hear that!
Thank you for your excellent tutorial! It helps my homework and research a lot!!
Thanks for the best PyTorch Tutorial 👍🏻👍🏻👍🏻
Glad you like it!
Thank you very much! literally the best place to learn pytorch
amazing tutorial man! thank you so much !!! this is just the best!
This is really great , appreciate your effort
Thanks 😊
What is the IDE/editor and the setup you are using? It looks great.
Very good tutorial, good job, thank you for this course!!
That is an excellent course. Thank you Python Engineer
This is a really well made video!
Great tutorial on the tensorboard part. But you made a mistake when plotting the precision and recall curve when you append predicted into the labels where it should have been labels1 - the actual labels of the eval batch
This is an error I have found
Time: 1:01:55
According to the equation,we actually need to find 1/N ,where N represents the number of term(here 4).According to the code,we are computing mean after converting the rest of the code to a dot product,which contains just a value.So instead of dividing with the desired value(4),we are dividing with 1.
Dude this has general helped me so much. Thank you!
Glad to hear it!
Thanks for this incredible resource. FYI I believe the gradient function computed at 1:01:38 is incorrect. I'm pretty sure it should be:
def gradient(x, y, y_predicted):
return ((y_predicted-y)*2*x).mean()
Thankyou Patrick. It was a fantastic tutorial.