On Tuesday 29 June 2004 05:05 pm, Sebastian Haase wrote:
Hi,
Is this a bug?:
# (import numarray as na ; 'd' is a 3 dimensional array) d.type()
Float32
d[80, 136, 122]
80.3997039795
na.maximum.reduce(d[:,136, 122])
85.8426361084
na.maximum.reduce(d) [136, 122]
37.3658103943
na.maximum.reduce(d,0)[136, 122]
37.3658103943
na.maximum.reduce(d,1)[136, 122]
Traceback (most recent call last): File "<input>", line 1, in ? IndexError: Index out of range
I was using na.maximum.reduce(d) to get a "pixelwise" maximum along Z (axis 0). But as seen above it does not get it right. I then tried to reproduce
this with some simple arrays, but here it works just fine:
a = na.arange(4*4*4) a.shape=(4,4,4) na.maximum.reduce(a)
[[48 49 50 51] [52 53 54 55] [56 57 58 59] [60 61 62 63]]
a = na.arange(4*4*4).astype(na.Float32) a.shape=(4,4,4) na.maximum.reduce(a)
[[ 48. 49. 50. 51.] [ 52. 53. 54. 55.] [ 56. 57. 58. 59.] [ 60. 61. 62. 63.]]
Any hint ?
Regards, Sebastian Haase
Hi again, I think the reason that no one responded to this is that it just sounds to unbelievable ... Sorry for the missing piece of information, but 'd' is actually a memmapped array !
d.info() class: <class 'numarray.numarraycore.NumArray'> shape: (80, 150, 150) strides: (90000, 600, 4) byteoffset: 0 bytestride: 4 itemsize: 4 aligned: 1 contiguous: 1 data: <MemmapSlice of length:7290000 readonly> byteorder: big byteswap: 1 type: Float32 dd = d.copy() na.maximum.reduce(dd[:,136, 122]) 85.8426361084 na.maximum.reduce(dd)[136, 122] 85.8426361084
Apparently we are using memmap so frequently now that I didn't even think about that - which is good news for everyone, because it means that it works (mostly). I just see that 'byteorder' is 'big' - I'm running this on an Intel Linux PC. Could this be the problem? Please some comments ! Thanks, Sebastian