Re: [Matplotlib-users] ploting a contour graph from data files

[Oz N. <na...@gm...>]

Thanks for the quick answer.
So if I have a series of 18 points withe measured distance, and 18 data
points with distance, it makes it almost impossible to build the graph ??? I
can't type 18^18 points.... I want the computer to plot the points and
extrapulate between them...

excuse me the possibly dumb question, I am new to sceintific programming and
for matplotlib

Oz


On Wed, Jul 16, 2008 at 7:51 PM, Eric Firing <ef...@ha...> wrote:

> Oz Nahum wrote:
>
>> Hi,
>> I want to draw a contour plot which uses data from files. I know how to
>> import the files, so it's not the main issue.
>> Let's say I want to do a profile which has the following data:
>> distance, depth and some oceanographic data like temp, oxygen and
>> stuff....
>>
>> so for simplicity lets say I have:
>>
>> distance = [1,2,3,4,5,6,7,8,9]
>> depth = [1,2,3,4,5,6,7,8,9]
>>
>> temp = [26.5, 26.2, 26.2, 26.0,25, 24, 22, 21, 18]
>>
>
> Too simple.  If your grid has 9 points in distance and 9 in depth, then you
> need 81 values of temperature (9 profiles of 9 depths each).
>
> Suppose you have 10 profiles of 8 points each.  Then your temperature array
> should have shape (8,10).  Your distance and depth arrays can either have
> the same shape as temperature, or both can be 1-D, in which case
> distance.shape = (10,) and depth.shape = (8,).  Either way, you then use
> (assuming a current release of mpl)
>
> from matplotlib import pyplot as plt
> plt.contour(distance, depth, temperature)
> plt.gca().invert_yaxis() # so depth increases down the y-axis
> plt.show()
>
> Note that the shape of your temperature array is the transpose of what one
> might expect.  This is for matlab compatibility, and goes with the idea of
> looking at an array as it is printed, with the column dimension (second
> index) increasing across the page.
>
> See the contour_demo.py and contourf_demo.py in the mpl examples.
>
> Eric
>
>
>
>> how do I produce a countour plot were distanc is X, Y is depth and the
>> contours are for temp ?
>>
>> many thanks...
>> Oz
>>
>