2.1.2. HDF5 in Python with h5py¶
One way to gain a quick familiarity with NeXus is to start working with some data. For at least the
first few examples in this section, we have a simple two-column set of 1-D data, collected as part of a
series of alignment scans by the APS USAXS instrument during the time it was stationed at
beam line 32ID. We will show how to write this
data using the Python language and the h5py package [1]
(using h5py calls directly rather than using the NeXus NAPI). The
actual data to be written was extracted (elsewhere) from a spec [2] data file
and read as a text block from a file by the Python source code.
Our examples will start with the simplest case and add only mild complexity with each new case
since these examples are meant for those who are unfamiliar with NeXus.
2.1.2.1. Code examples¶
2.1.2.2. Example data used¶
The data shown plotted in the next figure will be written to the NeXus HDF5 file
using only two NeXus base classes, NXentry and NXdata, in the first example
and then minor variations on this structure in the next two examples. The
data model is identical to the one in the Introduction
chapter except that the names will be different, as shown below:
data structure of the simple example¶
1 /entry:NXentry
2 /mr_scan:NXdata
3 /mr : float64[31]
4 /I00 : int32[31]
plot of the simple example data¶
Simple example values
1 17.92608 1037
2 17.92591 1318
3 17.92575 1704
4 17.92558 2857
5 17.92541 4516
6 17.92525 9998
7 17.92508 23819
8 17.92491 31662
9 17.92475 40458
10 17.92458 49087
11 17.92441 56514
12 17.92425 63499
13 17.92408 66802
14 17.92391 66863
15 17.92375 66599
16 17.92358 66206
17 17.92341 65747
18 17.92325 65250
19 17.92308 64129
20 17.92291 63044
21 17.92275 60796
22 17.92258 56795
23 17.92241 51550
24 17.92225 43710
25 17.92208 29315
26 17.92191 19782
27 17.92175 12992
28 17.92158 6622
29 17.92141 4198
30 17.92125 2248
31 17.92108 1321