createDataFrame.py

This code shows how to create a DataFrame object and add data to it.

This code shows how to create a DataFrame object and add data to it. create a DataFrame object with 4 columns and 3 rows and fill it with the following data:

Index	Diameter(μm)	Elongation factor	Type
1	6.52	0.93	Nucleus
2	2.47	0.37	Mitochondrion
3	5.78	0.86	Nucleus

Then another Formula column is added to give the result of the multiplication of Diameter and Elongation factor columns.

import iolink
from array import array
 
 
 
# Create a DataFrame object with 4 columns, using given values:
# - Indexer (int)
# - Diameter (double)
# - Elongation Factor (double)
# - Type (string)
def create_dataframeview(diameterValues, elongFactValues, typeValues) -> iolink.DataFrameView:
    # each list should have the same size
    if len(diameterValues) != len(elongFactValues) or len(diameterValues) != len(typeValues):
        raise ValueError("All lists should have the same size")
 
    numRows = len(diameterValues)
 
    # create a DataFrame object with 4 columns and the number of rows equal to the size of the given data
    columnNames = ["Index", "Diameter", "Elongation Factor", "Type"]
    columnTypes = [iolink.DataTypeId.UINT64, iolink.DataTypeId.DOUBLE, iolink.DataTypeId.DOUBLE, iolink.DataTypeId.UTF8_STRING]
    dataFrame = iolink.DataFrameViewFactory.allocate([4, numRows], columnNames, columnTypes)
 
    # set the unit of the Diameter column
    dataFrame.set_unit(dataFrame.column_index("Diameter"), "mm")
 
    # create the list of values of the index
    indexValues = list(range(1, numRows + 1))
 
        # fill each column with the given data, one shot
    dataFrame.write(dataFrame.column_index("Index"), 0, numRows, indexValues)
    dataFrame.write(dataFrame.column_index("Diameter"), 0, numRows, diameterValues)
    dataFrame.write(dataFrame.column_index("Elongation Factor"), 0, numRows, elongFactValues)
    dataFrame.write(dataFrame.column_index("Type"), 0, numRows, typeValues)
 
    return dataFrame
 
 
# Add a new column "formula" to the DataFrame object which is the result of the multiplication of the Diameter and
# Elongation Factor columns
def add_formula_to_dataFrame(df: iolink.DataFrameView):
    # add a new column "formula" to the DataFrame object
    df.add_column("Formula", iolink.DataTypeId.DOUBLE)
 
    # get the number of rows in the DataFrame object
    numRows = df.shape[1]
 
    # create a vector to store the result of the multiplication of the Diameter and Elongation Factor columns
    formulaValues = array('d',[0] * numRows)
 
    # calculate the result of the multiplication of the Diameter and Elongation Factor columns
    for i in range(0, numRows):
        formulaValues[i] = df.at("Diameter", i) * df.at("Elongation Factor", i)
        # write the result of the multiplication of the Diameter and Elongation Factor columns to the new column "formula"
        df.set_at("Formula", i, formulaValues[i])
 
# create dataframe
df = create_dataframeview([6.52, 2.47, 5.78], [0.93, 0.37, 0.86], ["Nucleus", "Mitochondrion", "Nucleus"])
 
# print the DataFrame object
print(df)
 
# add one column "formula" to the DataFrame object which contains the result of the multiplication of the Diameter
# and Elongation Factor columns
add_formula_to_dataFrame(df)
 
# print the DataFrame object after adding the new column "formula"
print(df)