如何把plot下面的Matlab编码变成python？

Question

My MATLAB code:

x=1:28:9996;
#y_test is 1x178 double array
padding=nan(1,179);
plot(x,[padding,y_test])

I am trying to do the same in python but it is not working. why?

#python
x=np.arange(1,9996,28)
padding=np.full((179),np.nan)
plt.plot(x,[padding,y_test])

It show this error:

ValueError: x and y must have same first dimension, but have shapes (1, 357) and (2,)

while the shape is y_test.shape, padding.shape,x.shape=>((1, 178), (1, 179), (1, 357)) thank you!

Answer 1

[padding,y_test] does not do the same thing in Python and in MATLAB. In MATLAB it concatenates the two arrays along the 1st dimension. In Python it creates a list containing the two arrays as its two elements.

To concatenate two NumPy arrays, use np.concatenate , np.stack , or column_stack .

In your case, you want to do np.concatenate((padding, y_test)) , assuming padding and y_test are 1D arrays (as your code generates). If they are 2D arrays with shape 1xN (as you claim in a comment), then specify you want to concatenate along the 2nd dimension: np.concatenate((padding, y_test), axis=1) .