Issue 1:
I used my set of data to plot a streamplot using matplotlib 1.4.3

the data range is from 0 to 1, grid points are equally spaced (except near corners which is dx/2 & dy/2)

the generated streamlines are correct but it seems that the whole streamplot is somehow scaled,, the range is shown to be from 0 to 0.5 instead of 0 to 1.

Here is my python code:

import numpy as np
import matplotlib.pyplot as plt
import linecache
str = linecache.getline("./result.dat", 2)
[n_x, n_y] = [int(s) for s in str.split() if s.isdigit()]
[X, Y, P, U, V] = np.genfromtxt("./result.dat", skip_header=2, unpack=True)
X = X.reshape(n_x,n_y)
Y = Y.reshape(n_x,n_y)
U = U.reshape(n_x,n_y)
V = V.reshape(n_x,n_y)
plt.streamplot(X, Y, U, V,color=U, linewidth=.6)
plt.colorbar()
plt.show()

and here is my data file called "result.dat":

VARIABLES = "Xp", "Yp", "P", "Up", "Vp"
ZONE I= 6 , J= 6 , F=POINT
0.00000000 0.00000000 0.00000000 0.00000000 0.00000000
0.12500000 0.00000000 0.00000000 0.00000000 0.00000000
0.37500000 0.00000000 0.00000000 0.00000000 0.00000000
0.62500000 0.00000000 0.00000000 0.00000000 0.00000000
0.87500000 0.00000000 0.00000000 0.00000000 0.00000000
1.00000000 0.00000000 0.00000000 0.00000000 0.00000000
0.00000000 0.12500000 0.00000000 0.00000000 0.00000000
0.12500000 0.12500000 0.00000000 -0.00163538 0.00163537
0.37500000 0.12500000 0.00271924 -0.00390620 0.00063544
0.62500000 0.12500000 0.00654694 -0.00391532 -0.00062633
0.87500000 0.12500000 0.00931612 -0.00164449 -0.00164449
1.00000000 0.12500000 0.00000000 0.00000000 0.00000000
0.00000000 0.37500000 0.00000000 0.00000000 0.00000000
0.12500000 0.37500000 -0.00274526 -0.00271282 0.00598356
0.37500000 0.37500000 0.00165029 -0.00629836 0.00214359
0.62500000 0.37500000 0.00754400 -0.00632485 -0.00209888
0.87500000 0.37500000 0.01205898 -0.00273931 -0.00602829
1.00000000 0.37500000 0.00000000 0.00000000 0.00000000
0.00000000 0.62500000 0.00000000 0.00000000 0.00000000
0.12500000 0.62500000 -0.01019055 -0.00543907 0.01413544
0.37500000 0.62500000 -0.00096611 -0.01172831 0.00386647
0.62500000 0.62500000 0.00987021 -0.01171517 -0.00380840
0.87500000 0.62500000 0.01944773 -0.00542593 -0.01419353
1.00000000 0.62500000 0.00000000 0.00000000 0.00000000
0.00000000 0.87500000 0.00000000 0.00000000 0.00000000
0.12500000 0.87500000 -0.02733655 0.00978724 0.00978725
0.37500000 0.87500000 -0.00486621 0.02193280 0.00235832
0.62500000 0.87500000 0.01378493 0.02195528 -0.00233585
0.87500000 0.87500000 0.03680858 0.00980972 -0.00980973
1.00000000 0.87500000 0.00000000 0.00000000 0.00000000
0.00000000 1.00000000 0.00000000 1.00000000 0.00000000
0.12500000 1.00000000 0.00000000 1.00000000 0.00000000
0.37500000 1.00000000 0.00000000 1.00000000 0.00000000
0.62500000 1.00000000 0.00000000 1.00000000 0.00000000
0.87500000 1.00000000 0.00000000 1.00000000 0.00000000
1.00000000 1.00000000 0.00000000 1.00000000 0.00000000

Result:

Thanks

Issue 2:
Are there any plans to support streamplotting data on irregular grids?

Currently, the streamplot documentations states:

Draws streamlines of a vector flow.

x, y : 1d arrays
an evenly spaced grid.

If my data is on an irregular grid, I currently have to interpolate to an evenly spaced grid before I can create a streamplot. This becomes a problem when the data is very large and interpolating takes a long time.

To add more roadbloacks, my x and y values are 2D arrays. Are there plans to support 2D x and ys as input to the streamplot?

(cc @pp-mo for reference)