Sasview 4.2

Zero and negative values not plotted appropriately in log scale for 2D data.

Plotter should add invalid values to the mask.

Could instead use a transform something like the following:

data = data.copy()
zmin = min(data[data>0])/2 if (data>0).any() else 1
data[data<=zmin] = zmin
return log10(data)

If you know it is counts data, then log10(data+1) is good enough for visualization.

You may still have a problem with spurious cancellation, for example when looking at background subtracted data, where you might end up with values like 1e-100 while the majority of the values are much higher. Setting the cutoff for masking at ½ the 5th percentile, np.quantile(data[data>0], 0.05)/2, instead of min(data[data>0])/2 would be better.

My users are complaining about SASView giving negative Y Axis for the following dataset: ​https://pastebin.com/raw/buBiU5JG

This is what sasviews gives:

​https://postimg.cc/R3TzMjSy

This is what I get with Matplotlib:

​https://postimg.cc/nsxJfHJq

This data is not a squared Maxtrix (looks more a sparse matrix):

In [3]: data = np.genfromtxt(filepath, skip_header=2, names="qx, qy, iqxqy, err"
   ...: )

In [4]: qx, qy, iqxqy, err = data['qx'], data['qy'], data['iqxqy'], data['err']

In [5]: len(np.unique(qx))
Out[5]: 78

In [6]: len(np.unique(qy))
Out[6]: 94

In [7]: len(qx)
Out[7]: 6978

In [8]: len(qy)
Out[8]: 6978

In [9]: 78*94
Out[9]: 7332

Selecting use dQ Data currently displays dQ high and dQ low (for pinhole data at least), However dQ low is not labelled while dQ high is labelled as dQ[%].

Prior to SasView version 4.1.0, the two values were labeled dQ high and dQ low. In 4.1.0 a change was made to the custom pinhole to be useful by asking for a dQ/Q in percent (see #850). The current labels probably were introduced accidentally in that work. However the proper fix should be to change the values presented to be dQ/Q[%] (as one label suggests) and then fix the labels to make it clear what is presented: dQ/Q low[%] and dQ/Q high[%].