Histogram Output Example

Location: examples/webapp/histogram/

This example demonstrates the <histogram> output type for bar charts, including single and grouped histograms.

Script

import sys
import numpy as np
import rappture2web.rp_library as Rappture

rx = Rappture.PyXml(sys.argv[1])
num_points = int(rx['input.(points).current'].value)
x = np.linspace(1, 10, num_points)

# Single histogram
hist = rx['output.histogram(single)']
hist['about.label'] = 'Single histogram'
hist['xaxis.label'] = 'Time'
hist['xaxis.units'] = 's'
hist['yaxis.label'] = 'Voltage v(11)'
hist['yaxis.units'] = 'V'
hist['component.xy'] = (x, np.cos(x) / (1 + x))

# Grouped histograms (overlaid on same axes)
for factor in [1, 2]:
    hist = rx['output.histogram(multi%s)' % factor]
    hist['about.group'] = 'Multiple histogram'
    hist['about.label'] = 'Factor a=%s' % factor
    hist['xaxis.label'] = 'Frequency'
    hist['yaxis.label'] = 'Current'
    hist['component.xy'] = (x, np.power(2.0, factor * x) / x)

rx.close()

Key concepts

• Set about.group to the same name on multiple histograms to overlay them on a single plot.

• Axis labels and units are configured the same way as curves.

Running

rappture2web examples/webapp/histogram/