square {gsignal}

Square wave

Description

Generate a square wave of period 2\pi with limits +1 and -1.

Usage

square(t, duty = 50)

Arguments

t

Time array, specified as a vector.

duty

Duty cycle, specified as a real scalar from 0 to 100. Default: 50.

Details

y <- square(t) generates a square wave with period 2\pi for the elements of the time array t. square is similar to the sine function but creates a square wave with values of –1 and 1.

y <- square(t, duty) generates a square wave with specified duty cycle duty. The duty cycle is the percent of the signal period in which the square wave is positive.

                     ontime * 100
     duty cycle =  ----------------
                   ontime + offtime

Value

Square wave, returned as a vector.

Author(s)

Paul Kienzle.
Conversion to R by Geert van Boxtel, [e-mail].

Examples

## Create a vector of 100 equally spaced numbers from 0 to 3pi.
## Generate a square wave with a period of 2pi.
t <- seq(0, 3*pi, length.out = 100)
y <- square(t)
plot(t/pi, y, type="l", xlab = expression(t/pi), ylab = "")
lines (t/pi, sin(t), col = "red")

## Generate a 30 Hz square wave sampled at 1 kHz for 70 ms.
## Specify a duty cycle of 37%.
## Add white Gaussian noise with a variance of 1/100.
t <- seq(0, 0.07, 1/1e3)
y <- square(2 * pi * 30 * t, 37) + rnorm(length(t)) / 10
plot(t, y, type="l", xlab = "", ylab = "")