R programming - Create Correlation Matrix from Dataframe
Write a R program to create a correlation matrix from a dataframe of same data type.
Sample Solution:
R Programming Code:
# Create a dataframe with three columns x1, x2, and x3, each containing 5 random normal values
d = data.frame(x1=rnorm(5),
x2=rnorm(5),
x3=rnorm(5))
# Print a message indicating that the following output is the original dataframe
print("Original dataframe:")
# Print the content of the dataframe
print(d)
# Calculate the correlation matrix of the dataframe
result = cor(d)
# Print a message indicating that the following output is the correlation matrix
print("Correlation matrix:")
# Print the correlation matrix
print(result)
Output:
[1] "Original dataframe:" x1 x2 x3 1 -0.0905430 1.7469241 -0.1360780 2 -0.1936120 0.9111132 0.5282113 3 0.7688536 -0.9413734 -0.8032169 4 2.0247769 -0.3096149 -0.8617996 5 -0.1824352 1.6179504 -0.2554897 [1] "Correlation matrix:" x1 x2 x3 x1 1.0000000 -0.7422855 -0.7789883 x2 -0.7422855 1.0000000 0.6600909 x3 -0.7789883 0.6600909 1.0000000
Explanation:
- Create DataFrame:
- d = data.frame(x1=rnorm(5), x2=rnorm(5), x3=rnorm(5))
- Creates a dataframe d with three columns (x1, x2, x3).
- Each column contains 5 random values drawn from a normal distribution (rnorm(5)).
- Print DataFrame Label:
- print("Original dataframe:")
- Prints a label indicating that the next output will display the original dataframe.
- Print DataFrame:
- print(d)
- Prints the contents of the dataframe d.
- Calculate Correlation Matrix:
- result = cor(d)
- Computes the correlation matrix for the dataframe d, showing pairwise correlations between columns.
- Print Correlation Matrix Label:
- print("Correlation matrix:")
- Prints a label indicating that the next output will display the correlation matrix.
- Print Correlation Matrix:
- print(result)
- Prints the calculated correlation matrix.
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