Hi all, How do I use genfromtxt to read a file with the following lines 1 1 2.2592365264892578D+01 2 2 2.2592365264892578D+01 1 3 2.6666669845581055D+00 3 3 2.2592365264892578D+01 2 4 2.6666669845581055D+00 4 4 2.2592365264892578D+01 3 5 2.6666669845581055D+00 5 5 2.2592365264892578D+01 4 6 2.6666669845581055D+00 6 6 2.2592365264892578D+01 1 7 2.9814243316650391D+00 7 7 1.7259031295776367D+01 2 8 2.9814243316650391D+00 8 8 1.7259031295776367D+01 ... names =("i","j","v") A = np.genfromtxt('bmll.mtl',dtype=[('i','int'),('j','int'),('v','d')],names=names) V = A[:]['v']
V array([ NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN])
yields NaN, while convertfunc = lambda x: x.replace('D','E') names =("i","j","v") A = np.genfromtxt('bmll.mtl',dtype=[('i','int'),('j','int'),('v','|S24')],names=names,converters={"v":convertfunc}) V = A[:]['v'].astype(float)
V array([ 22.59236526, 22.59236526, 2.66666698, 22.59236526, 2.66666698, 22.59236526, 2.66666698, 22.59236526, 2.66666698, 22.59236526, 2.98142433, 17.2590313 , 2.98142433, 17.2590313 , 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.66666698, 17.2590313 , 2.98142433, 2.66666698, 17.2590313 ])
works fine. Nils
Hi Nils, On 11 Oct 2011, at 16:34, Nils Wagner wrote:
How do I use genfromtxt to read a file with the following lines
1 1 2.2592365264892578D+01 2 2 2.2592365264892578D+01 1 3 2.6666669845581055D+00 3 3 2.2592365264892578D+01 2 4 2.6666669845581055D+00 4 4 2.2592365264892578D+01 3 5 2.6666669845581055D+00 5 5 2.2592365264892578D+01 4 6 2.6666669845581055D+00 6 6 2.2592365264892578D+01 1 7 2.9814243316650391D+00 7 7 1.7259031295776367D+01 2 8 2.9814243316650391D+00 8 8 1.7259031295776367D+01 ...
names =("i","j","v") A = np.genfromtxt('bmll.mtl',dtype=[('i','int'),('j','int'),('v','d')],names=names) V = A[:]['v']
V array([ NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN, NaN])
yields NaN, while
convertfunc = lambda x: x.replace('D','E') names =("i","j","v") A = np.genfromtxt('bmll.mtl',dtype=[('i','int'),('j','int'),('v','|S24')],names=names,converters={"v":convertfunc}) V = A[:]['v'].astype(float)
V array([ 22.59236526, 22.59236526, 2.66666698, 22.59236526, 2.66666698, 22.59236526, 2.66666698, 22.59236526, 2.66666698, 22.59236526, 2.98142433, 17.2590313 , 2.98142433, 17.2590313 , 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.98142433, 2.66666698, 22.59236526, 2.98142433, 2.66666698, 17.2590313 , 2.98142433, 2.66666698, 17.2590313 ])
works fine.
took me a moment to figure out what the actual problem remaining was, but expect you'd prefer it to load directly into a float record? The problem is simply that the converter _replaces_ the default converter function (which would be float(x) in this case), rather than operating on top of it. Try instead convertfunc = lambda x: float(x.replace('D','E')) and you should be ready to use ('v', 'd') as dtype (BTW, specifying 'names' is redundant in the above example). This behaviour is only hinted at in the docstring example, so maybe the documentation should be clearer here. Cheers, Derek
participants (2)
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Derek Homeier -
Nils Wagner