# C1\_W3 \_Assignment **URL:** \ **Category:** Linear Algebra for Machine Learning and Data Sc...\ **Tags:** week-module-3\ **Created:** [April 21, 2023, 6:20pm UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542 "2023-04-21T18:20:11Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Somasekhar\_Donthu](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@Somasekhar\_Donthu](https://community.deeplearning.ai/u/Somasekhar_Donthu)\ **Post date:** [April 21, 2023, 6:20pm UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/1 "2023-04-21T18:20:12Z")
# Single Perceptron Neural Networks for Linear Regression Assignment getting below error exercise 4 in 2.3 the loop shapes (1,1) and (30,1) not aligned: 1 (dim 1) != 30 (dim 0) please guide me ---
**Author:** ![yjcb22](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/yjcb22/32/127956_2.png) [@yjcb22](https://community.deeplearning.ai/u/yjcb22)\ **Post date:** [April 21, 2023, 10:54pm UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/2 "2023-04-21T22:54:09Z")
Can you please tell me the line where you are getting the error? Is it when computing Z? or in the assert? Normally the error will say the line. ---
**Author:** ![Somasekhar\_Donthu](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@Somasekhar\_Donthu](https://community.deeplearning.ai/u/Somasekhar_Donthu)\ **Post date:** [April 22, 2023, 4:36am UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/3 "2023-04-22T04:36:43Z")
ValueError Traceback (most recent call last) in ----\> 1 Y\_hat = forward\_propagation(X, parameters) 2 3 print(Y\_hat) in forward\_propagation(X, parameters) 19 ### START CODE HERE ### (~ 2 lines of code) 20 Z = np.dot(w, X) + b —\> 21 Y\_hat = forward\_propagation(X.T, parameters) 22 ### END CODE HERE ### 23 in forward\_propagation(X, parameters) 18 # Implement Forward Propagation to calculate Z. 19 ### START CODE HERE ### (~ 2 lines of code) —\> 20 Z = np.dot(w, X) + b 21 Y\_hat = forward\_propagation(X.T, parameters) 22 ### END CODE HERE ### \< **array\_function** internals\> in dot(\*args, \*\*kwargs) ValueError: shapes (1,1) and (30,1) not aligned: 1 (dim 1) != 30 (dim 0) ---
**Author:** ![Somasekhar\_Donthu](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@Somasekhar\_Donthu](https://community.deeplearning.ai/u/Somasekhar_Donthu)\ **Post date:** [April 22, 2023, 5:37am UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/4 "2023-04-22T05:37:03Z")
I AM GETTING ALL ERRORS WHEN I GO FOR GRADING BUT IT IS SHOWING ALL TESTS PASSED ERROR There was a problem compiling the code from your notebook. Details: matmul: Input operand 1 has a mismatch in its core dimension 0, with gufunc signature (n?,k),(k,m?)-\>(n?,m?) (size 2 is different from 1) I HOPE THERE Z A PROBLEM WITH COURSERA … ---
**Author:** ![yjcb22](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/yjcb22/32/127956_2.png) [@yjcb22](https://community.deeplearning.ai/u/yjcb22)\ **Post date:** [April 22, 2023, 1:48pm UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/5 "2023-04-22T13:48:54Z")
Dear @Somasekhar_Donthu Please find my comments: 1. I doubt there is an error in the coursera platform because the platform is the same for everybody and I am not getting any error as you can see in the following image: ![image](https://global.discourse-cdn.com/dlai/original/3X/1/1/1130923a740634fd8b52da06455c727a63547605.png) However, everything is possible. 1. Can you please try using np.matmul(W,X) + b instead of the dot product and tell me if you are getting the same error? 2. The initial code defines W with upper case, however, I see you are using it with lower case. Can you please confirm if you change the source code? If so, can you please define W and b like this: W = parameters[“W”] b = parameters[“b”] ---
**Author:** ![Syed\_Hassan\_Raahim](https://avatars.discourse-cdn.com/v4/letter/s/bc79bd/32.png) [@Syed\_Hassan\_Raahim](https://community.deeplearning.ai/u/Syed_Hassan_Raahim)\ **Post date:** [April 23, 2023, 1:02pm UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/6 "2023-04-23T13:02:05Z")
Not using np.matmul() was the issue ---
**Author:** ![yjcb22](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/yjcb22/32/127956_2.png) [@yjcb22](https://community.deeplearning.ai/u/yjcb22)\ **Post date:** [April 23, 2023, 5:04pm UTC](https://community.deeplearning.ai/t/c1-w3-assignment/312542/7 "2023-04-23T17:04:19Z")
@Syed_Hassan_Raahim Awesome! It was my pleasure to help you my friend!