/*############################# draw_stat() #############################*/
void
draw_stat(void)
{
draw_x_axis();
draw_x_values();
draw_y_axis();
draw_graph();
return;
}
// Create and output the bar chart from the list
void bar_chart(Bar *pFirst, uint page_width, uint page_height, char *title)
{
Bar *pLast = pFirst; // Pointer to previous Bar
double max = pFirst->value; // Maximum Bar value - 1st to start
double min = pFirst->value; // Minimum Bar value - 1st to start
double vert_step = 0.0; // Unit step in vertical direction
uint bar_count = 1; // Number of bars - at least 1
uint bar_width = 0; // Width of a Bar
uint space = 2; // Spaces between bars
char *column = NULL; // Pointer to Bar column section
char *blank = NULL; // Blank string for Bar+space
double position = 0.0; // Current vertical position on chart
bool axis = false; // Indicates axis drawn
// Find maximum and minimum of all Bar values
while(pLast = pLast->pNext)
{
++bar_count; // Increment Bar count
max = (max < pLast->value) ? pLast->value : max;
min = (min > pLast->value) ? pLast->value : min;
}
// Always draw chart to horizontal axis
if(max < 0.0) max = 0.0;
if(min > 0.0) min = 0.0;
vert_step = (max - min)/page_height; // Calculate step length
// Calculate and check Bar width
if((bar_width = page_width/bar_count - space) < 1)
{
printf_s("\nPage width too narrow.\n");
exit(1);
}
// Set up a string that will be used to build the columns
if(!(column = chart_string(space, bar_width, '#')))
{
printf_s("\nFailed to allocate memory in barchart()"
" - terminating program.\n");
exit(1);
}
// Set up a string that will be a blank column
if(!(blank = chart_string(space, bar_width, ' ')))
{
printf_s("\nFailed to allocate memory in barchart()"
" - terminating program.\n");
exit(1);
}
// Draw the Bar chart. It is drawn line by line starting at the top
printf_s("\n^ %s\n", title); // Output the chart title
position = max; // Start at the top
for(uint i = 0 ; i < page_height ; ++i) // page_height lines for chart
{
// Check if we need to output the horizontal axis
if(position <= 0.0 && !axis)
{
draw_x_axis(bar_count*(bar_width + space));
axis = true;
}
printf_s("|"); // Output vertical axis
pLast = pFirst; // start with the first Bar
// For each Bar...
for(uint bars = 1 ; bars <= bar_count ; ++bars)
{
// If position is between axis and value, output column. otherwise blank
printf_s("%s", position <= pLast->value && position > 0.0 ||
position >= pLast->value && position <= 0.0 ? column : blank);
pLast = pLast->pNext;
}
printf_s("\n"); // End the line of output
position -= vert_step; // Decrement position
}
if(!axis) // Horizontal axis?
draw_x_axis(bar_count*(bar_width + space)); // No, so draw it
else
printf_s("v\n"); // -y axis arrow head
free(blank); // Free blank string memory
free(column); // Free column string memory
}
