Question

Use matrix subtraction to calculate how much longer was the life expectancy of black

and white women than men of the same races in each decade from year 1950 to year

2000. There is no need to store the year data in your matrices—just provide the years in

the output.

a) Input each matrix from user

b) Calculate the matrix difference by calling a function you write called matrix_diff that

will subtract any two 6-by-2 matrices, producing a third 6-by-2 matrix.

c) Display all three matrices with appropriate labels. Your function should calculate the

matrix difference by subtracting each element of the second matrix from the

corresponding element of the first.

United States Life Expectancy at Birth by Sex and Race

Answer 1

#include <stdio.h>
#define ROW 2
#define COL 6
void matrix_diff(double[][COL], double[][COL], double[][COL]);
void display(double[][COL]);
int main()
{
    FILE *male = fopen("male.txt", "r"), *female = fopen("female.txt", "r");
    double MALE_MAT[ROW][COL], FEMALE_MAT[ROW][COL], DIFF_MAT[ROW][COL];
    int i, j;

    while(!feof(male))
    {
        for(i = 0; i < ROW; i++)
            for(j = 0; j < COL; j++)
                fscanf(male, "%lf", &MALE_MAT[i][j]);
    }

    while(!feof(female))
    {
        for(i = 0; i < ROW; i++)
            for(j = 0; j < COL; j++)
                fscanf(female, "%lf", &FEMALE_MAT[i][j]);
    }

    matrix_diff(MALE_MAT, FEMALE_MAT, DIFF_MAT);

    printf("\nMale");
    display(MALE_MAT);

    printf("\n\nFemale");
    display(FEMALE_MAT);

    matrix_diff(MALE_MAT, MALE_MAT, DIFF_MAT);

    printf("\nDifference");
    display(FEMALE_MAT);

    fclose(male);
    fclose(female);
}

void matrix_diff(double A[][COL], double B[][COL], double C[][COL])
{
    int i, j;
    for(i = 0; i < ROW; i++)
    {
        for(j = 0; j < COL; j++)
        {
            C[i][j] = A[i][j] - B[i][j];
        }
    }
}

void display(double A[][COL])
{
    int i, j, year = 1950;
    printf("\nYear %3c Black %3c White\n", ' ', ' ');
    for(i = 0; i < COL; i++)
    {
        printf("\n%d %2c", year, ' ');
        for(j = 0; j < ROW; j++)
        {
            printf("%.1f  ", A[i][j]);
        }
        year += 10;
    }
}

This program reads files:

1. female.txt

62.9 72.2
66.3 74.1
68.3 75.6
72.5 78.1
73.6 79.4
75.2 80.1

2.male.txt

59.1 66.5
61.1 67.4
60.0 68.0
63.8 70.7
64.5 72.7
68.3 74.9