Commitacf92c6

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Mask values < vmin in PowerNorm

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+22

-8

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+22

-8

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Lines changed: 5 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,5 @@`
	`1`	+``PowerNorm`` clipping
	`2`	`+~~~~~~~~~~~~~~~~~~~~~~`
	`3`	+When ``clip=False`` (the default) was set on `~.PowerNorm`, values
	`4`	+less than ``vmin`` were previously clipped to zero without being masked.
	`5`	`+This has been fixed to mask these values in the result.`

Lines changed: 9 additions & 5 deletions

Original file line number	Diff line number	Diff line change
`@@ -1885,12 +1885,16 @@ def __call__(self, value, clip=None):`
`1885`	`1885`	`result=np.ma.array(np.clip(result.filled(vmax),vmin,vmax),`
`1886`	`1886`	`mask=mask)`
`1887`	`1887`	`resdat=result.data`
`1888`		`-resdat-=vmin`
`1889`		`-resdat[resdat<0]=0`
`1890`		`-np.power(resdat,gamma,resdat)`
`1891`		`-resdat/= (vmax-vmin)**gamma`
	`1888`	`+# These values are masked later, but set to zero now to prevent`
	`1889`	`+# invalid value warnings when taking the power`
	`1890`	`+under_mask=resdat<vmin`
	`1891`	`+resdat[under_mask]=vmin`
`1892`	`1892`
`1893`		`-result=np.ma.array(resdat,mask=result.mask,copy=False)`
	`1893`	`+resdat= (resdat-vmin)/ (vmax-vmin)`
	`1894`	`+resdat=resdat**gamma`
	`1895`	`+`
	`1896`	`+mask=result.mask\|under_mask`
	`1897`	`+result=np.ma.array(resdat,mask=mask,copy=False)`
`1894`	`1898`	`ifis_scalar:`
`1895`	`1899`	`result=result[0]`
`1896`	`1900`	`returnresult`

Lines changed: 8 additions & 3 deletions

Original file line number	Diff line number	Diff line change
`@@ -551,11 +551,16 @@ def test_PowerNorm():`
`551`	`551`	`assert_array_almost_equal(norm(a),pnorm(a))`
`552`	`552`
`553`	`553`	`a=np.array([-0.5,0,2,4,8],dtype=float)`
`554`		`-expected= [0,0,1/16,1/4,1]`
`555`	`554`	`pnorm=mcolors.PowerNorm(2,vmin=0,vmax=8)`
`556`		`-assert_array_almost_equal(pnorm(a),expected)`
`557`		`-assertpnorm(a[0])==expected[0]`
	`555`	`+expected= [0,0,1/16,1/4,1]`
	`556`	`+expected_mask= [True,False,False,False,False]`
	`557`	`+`
	`558`	`+normed=pnorm(a)`
	`559`	`+assert_array_almost_equal(normed,expected)`
	`560`	`+assert_array_equal(normed.mask,expected_mask)`
	`561`	`+assertpnorm(a[1])==expected[1]`
`558`	`562`	`assertpnorm(a[2])==expected[2]`
	`563`	`+`
`559`	`564`	`assert_array_almost_equal(a[1:],pnorm.inverse(pnorm(a))[1:])`
`560`	`565`
`561`	`566`	`# Clip = True`

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