.. _04_pim_sol:

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Python in Mantid: Solution 4
============================

All the data for these solutions can be found in the TrainingCourseData on the Downloads page.

Manipulating data arrays
========================

A - Create a MatrixWorkspace
----------------------------

.. code-block:: python

    # import mantid algorithms, numpy and matplotlib
    from mantid.simpleapi import *
    import matplotlib.pyplot as plt
    import numpy as np

    ws = Load(Filename="HRP39182.RAW")
    ws = Rebin(InputWorkspace=ws, Params=1e4)
    nbins = ws.blocksize()
    print(nbins)

    xMin = ws.getDimension(0).getMinimum()
    xMax = ws.getDimension(0).getMaximum()
    xRange = [xMin, xMax]

    ''' ----------- Part One Solution using nested loop and implementing a max condition by hand ----------- '''
    new_y = []
    for i in range(ws.getNumberHistograms()):
        y = ws.readY(i)
        maxY = -1
        # Inner loop. Loop over bins.
        for j in range(nbins):
            current = y[j]
            if current > maxY:
                maxY = current
        new_y.append(maxY)

    solution_1 = CreateWorkspace(DataY=new_y, DataX=xRange, NSpec=ws.getNumberHistograms())

    ''' ----------- Part One Solution  using nested loop and implementing an inbuild max function ----------- '''
    new_y = []
    for i in range(ws.getNumberHistograms()):
        y = ws.readY(i)
        maxY = -1.0
        # Inner loop. Loop over bins.
        for j in range(nbins):
            maxY = max(y[j], maxY) # Using the input Max method.
        new_y.append(maxY)

    solution_2 = CreateWorkspace(DataY=new_y, DataX=xRange, NSpec=ws.getNumberHistograms())

    ''' ----------- Part One Solution  using single loop and numpy max function ----------- '''
    new_y = []
    for i in range(ws.getNumberHistograms()):
        y = ws.readY(i)
        maxY = np.max(y)
        new_y.append(maxY)

    solution_3 = CreateWorkspace(DataY=new_y, DataX=xRange, NSpec=ws.getNumberHistograms())

B - Create a TableWorkspace
---------------------------

.. code-block:: python

    ws = Load(Filename="HRP39182.RAW")
    ws = Rebin(InputWorkspace=ws, Params=1e4)
    nbins = ws.blocksize()
    print(nbins)

    xMin = ws.getDimension(0).getMinimum()
    xMax = ws.getDimension(0).getMaximum()
    xRange = [xMin, xMax]

    table = CreateEmptyTableWorkspace()
    table.addColumn('int', 'Spectrum Number')
    table.addColumn('double', 'Max')
    table.addColumn('double', 'Min')
    for i in range(ws.getNumberHistograms()):
        y = ws.readY(i)
        maxY = np.max(y)
        minY = np.min(y)
        specNumber = ws.getSpectrum(i).getSpectrumNo()
        table.addRow([specNumber, maxY, minY])