MATLAB Function Reference
semilogx, semilogy

Semi-logarithmic plots

Syntax

• ```semilogx(Y)
semilogx(X1,Y1,...)
semilogx(X1,Y1,`LineSpec`,...)
semilogx(...,'PropertyName',PropertyValue,...)
h = semilogx(...)

semilogy(...)
h = semilogy(...)
```

Description

`semilogx` and `semilogy` plot data as logarithmic scales for the x- and y-axis, respectively. logarithmic

```semilogx(Y) ``` creates a plot using a base 10 logarithmic scale for the x-axis and a linear scale for the y-axis. It plots the columns of `Y` versus their index if `Y` contains real numbers. `semilogx(Y)` is equivalent to `semilogx(real(Y)`, `imag(Y))` if `Y` contains complex numbers. `semilogx` ignores the imaginary component in all other uses of this function.

```semilogx(X1,Y1,...) ``` plots all `Xn` versus `Yn` pairs. If only `Xn` or `Yn` is a matrix, `semilogx` plots the vector argument versus the rows or columns of the matrix, depending on whether the vector's row or column dimension matches the matrix.

```semilogx(X1,Y1,LineSpec,...) ``` plots all lines defined by the `Xn,Yn,LineSpec` triples. `LineSpec` determines line style, marker symbol, and color of the plotted lines.

```semilogx(...,'PropertyName',PropertyValue,...) ``` sets property values for all line graphics objects created by `semilogx`.

```semilogy(...) ``` creates a plot using a base 10 logarithmic scale for the y-axis and a linear scale for the x-axis.

```h = semilogx(...) and h = semilogy(...) ``` return a vector of handles to line graphics objects, one handle per line.

Remarks

If you do not specify a color when plotting more than one line, `semilogx` and `semilogy` automatically cycle through the colors and line styles in the order specified by the current axes ColorOrder and LineStyleOrder properties.

You can mix `Xn,Yn` pairs with `Xn`,`Yn`,`LineSpec` triples; for example,

• ````semilogx`(X1,Y1,X2,Y2,`LineSpec`,X3,Y3)
```

Examples

Create a simple `semilogy` plot.

• ```x = 0:.1:10;
semilogy(x,10.^x)

```

• ````line`, `LineSpec`, `loglog`, ```plot