Matplotlib Contour Plots

[Steven D'Aprano]

Jamie Mitchell wrote:

> I created the 2D array which read as:

That's not a 2D array.

When the amount of data you have is too big to clearly see what it
happening, replace it with something smaller. Instead of 30 items per
sub-array, try it with 5 items per sub-array. Instead of eight decimal
places, try it with single-digit integers. Anything to make it small enough
to see clearly.

When I do that with your data, instead of this:

> array([[[ 2.08800006,  2.29400015,  2.00400019,  1.88000011,  2.0480001 ,
>           2.16800022,  2.0480001 ,  1.88200009,  1.95800006,  2.00200009,
>           2.02800012,  1.81200004,  1.95000005,  1.96200013,  1.95200014,
>           1.99800014,  2.07000017,  1.88200009,  1.98400009,  2.13400006,
>           2.11400008,  1.89400005,  2.05000019,  2.01999998,  2.03400016,
>           2.16600013,  2.00999999,  1.86200011,  2.19800019, 
>           2.01200008]],
> 
>        [[ 8.5199995 ,  8.88000011,  8.55000019,  7.94999981,  8.60999966,
>           8.5199995 ,  8.80000019,  8.13000011,  8.68999958,  8.72999954,
>           8.47999954,  8.25      ,  8.40999985,  8.43999958,  8.38999939,
>           8.35999966,  8.63999939,  8.51000023,  8.36999989,  8.69999981,
>           8.52999973,  8.13999939,  8.36999989,  8.42000008,  8.55999947,
>           8.72999954,  9.09000015,  8.18999958,  8.76000023, 
>           8.53999996]]], dtype=float32)


I get this:


array([[[ 2,  2,  2,  1,  2]],
       [[ 8,  8,  8,  7,  8]]], dtype=float32)


which is much easier to work with. See the difference between that smaller
example, and my earlier explanation of the difference between a 1D and 2D
array?

One dimensional arrays are made from a single list of numbers: [...]
Two dimensional arrays are made from a list of lists: [ [...], [...] ]

*Three* dimensional arrays are made from a list of lists of lists: 
[ [ [...], [...] ] ]

*Four* dimensional arrays are made from a list of lists of lists of lists:
[ [ [ [...], [...] ] ] ]

and so on. You have a 3D array, with dimensions 2 x 1 x 30.

You can check the dimensions by storing the array into a variable like this:

py> a = numpy.array([[[ 2,  2,  2,  1,  2]], [[ 8,  8,  8,  7,  8]]])
py> a.shape
(2, 1, 5)



-- 
Steven