sq

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Description

Calculates the square of a number: the number multiplied by itself.

Notes:

• Because of the way the sq() function is implemented, using other functions inside the brackets may lead to incorrect results. For example, avoid sq(a++).

Inclusion

• defined in misc.h
• auto-loaded in main_general.h
• no #define required

Syntax

y = sq(x)

Parameters

• input:

  • x: the number, any data type

• output:

  • none

Returns

• The square of the number. (float)

Example Code

The below code prints a table for y=x*x. Note that the example requires option #define USE_FTOA in file config.h for floating point output.

#include "main_general.h"
#include "uart1.h"
#include "putchar.h"

void setup() {

  float x,y;
  char  s1[20], s2[20];
  
  // init UART and printf()
  UART1_begin(115200);
  putcharAttach(UART1_write);
  
  // allow the terminal to launch
  sw_delay(1000);
  
  // print math table
  for (x=-5.0; x<=5.0; x+=0.5) {
    y = sq(x);
    printf("%s  %s\n", floatToString(s1,x,2), floatToString(s2,y,2));
  }
  
}

void loop() {
  // dummy
}

Relevant Tutorial

• tbd

See also

• pow()
• sqrt()
• exp()
• log()
• log10()