# [SciPy-User] [SciPy-user] ValueError: arrays must have same number of dimensions

Jorge E. ´Sanchez Sanchez hnry2k@hotmail....
Thu Jun 28 10:48:17 CDT 2012

```Hi,

it seems to me that you don't know that loops in python end before the last index value of the loop,
you just need to do something like:
Np1 = N+1
for j in range (1, Np1):

HTH
Best Regards
Jorge

> Date: Thu, 28 Jun 2012 08:32:47 -0700
> From: surfcast23@gmail.com
> To: scipy-user@scipy.org
> Subject: [SciPy-User] [SciPy-user] ValueError: arrays must have same number	of dimensions
>
>
> Hi I am trying to translate a Matlab code from Trefethen's Spectral Methods
> in MATLAB to Python. I am running into a problem with numpy.concatenate
> wanting the arrays to have the same number of dimensions.
> Here is part of the Matlab code that I am rewriting
>
>
> N = 512; h = 2*pi/N; x = h*(1:N); t = 0; dt = h/4;
> a = .1;
> c = a + sin (x-1).^2;
> v = exp(-100*(x-1).^2); vold = exp(-100*(x-a*dt-1).^2);
>
> column = [0 .5*(-1).^(1:N-1).*cot((1:N-1)*h/2)];
> D = toeplitz(column,-column);
>
> % Time-stepping by leap frog formula:
> tmax = 15; tplot = .15; clf, drawnow, set(gcf,'renderer','zbuffer')
> plotgap = round(tplot/dt); dt = tplot/plotgap;
> nplots = round(tmax/tplot);
> data = [v; zeros(nplots,N)]; tdata = t;
>
>
> What I am trying in Python
>
> for j in range(1,N):
>  tmax = 15;
>  tplot = .15;
>  h = 2*pi/N;
>  dt = h/4;
>  nplots = around(tmax/tplot);
>  plotgap = around(tplot/dt);
>  dt = tplot/plotgap;
>  x = h*arange(1,N);
>  c = a+np.sin(x-1)**2;
>  v = exp(-100*(x-1)**2);
>  vold = exp(-100*(x-a*dt-1)**2);
>
>  column = ((0.5*(-1)**arange(1,N-1))*cotdg(arange(1,N-1))*(h/2));
>  D = toeplitz(column,-column);
>
>  k = np.zeros(((nplots,N)));
>  data = np.concatenate((v, k),axis = 0);
>  tdata = t;
>
>
> I have highlighted the vectors in question.
> v.shape gives (511,)
>
> k.shape gives (100, 512)
>
> I would appreciate any help with this. Thank you!
>
> --
> View this message in context: http://old.nabble.com/ValueError%3A-arrays-must-have-same-number-of-dimensions-tp34086886p34086886.html
> Sent from the Scipy-User mailing list archive at Nabble.com.
>
> _______________________________________________
> SciPy-User mailing list
> SciPy-User@scipy.org
> http://mail.scipy.org/mailman/listinfo/scipy-user

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/scipy-user/attachments/20120628/3cd383bf/attachment.html
```