thx for theses examples, but now i don't found how to scale my plot, i
used list_plot
On 10 avr, 18:38, Joshua Kantor <[EMAIL PROTECTED]> wrote:
> This should work for you
>
> sage: import numpy
> sage: a=numpy.loadtxt('my_file.txt')
> sage: x_vals=a[:,1]
> sage: y_vals=a[:,2]
>
> note that now x_vals and y_vals are numpy arrays. At this point you
> have a few ways of
> of doing the ftt
>
> Option 1
> sage: from numpy import fft
> sage: fft.fft(x_xvals)
> sage: fft.fft(y_vals)
>
> Option 2
> If you prefer sage vectors do it this way
>
> sage: import numpy
> sage: a=numpy.loadtxt('my_file.txt')
> sage: x_vals=vector(RDF,a[:,1])
> sage: y_vals=vector(RDF,a[:,2])
> sage: x_vals.fft()
> sage: y_vals.fft()
>
> If you are familiar with matlab, you should look at numpy and scipy
> (import numpy, import scipy). And you might find this
> helpfulhttp://www.scipy.org/NumPy_for_Matlab_Users
>
> On Apr 10, 9:25 am, Nicoo <[EMAIL PROTECTED]> wrote:
>
> > simple txt file with columns
> > first column is the time, second the X velocity value, third the Y
> > velocity value
> > and I want to fft each components of velocity to get the frequency of
> > oscillations.
> > (sry for my bad english)
>
> > On 10 avr, 18:16, "William Stein" <[EMAIL PROTECTED]> wrote:
>
> > > On Thu, Apr 10, 2008 at 9:15 AM, Nicoo <[EMAIL PROTECTED]> wrote:
>
> > > > thx, I will try the fft() method, other question, how can I load my
> > > > datas in a vector ?
>
> > > What format are your datas in?
>
> > > -- William
>
> > > > On 10 avr, 17:40, "William Stein" <[EMAIL PROTECTED]> wrote:
>
> > > > > On Thu, Apr 10, 2008 at 8:26 AM, Nicoo <[EMAIL PROTECTED]> wrote:
> > > > > > Hello there,
> > > > > > -I used matlab to fft some datas, I have .m file from matlab, is
> > > > it
> > > > > > possible to load it in sagemath and use it ?
>
> > > > > No, the Sage programming language is Python, which is as
> > > > > different from Matlab's language as Mathematica is different
> > > > > than Matlab.
>
> > > > > Sage does have fft functionality itself though:
>
> > > > > sage: v = vector(RDF, 10000, range(10000))
> > > > > sage: time w = v.fft()
> > > > > CPU time: 0.00 s, Wall time: 0.00 s
>
> > > > > It's also possible to use the Sage interfaces to Matlab/Octave...
>
> > > > > -- William
>
> > > --
> > > William Stein
> > > Associate Professor of Mathematics
> > > University of Washingtonhttp://wstein.org
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