Understanding and Implementing Y-Axis Logarithmic Scaling in Matlab

Matlab, a high-performance language for technical computing, is an excellent tool in the hands of engineers, scientists, and programmers. It provides an interactive environment suitable for algorithm development, data visualization, prototyping, and application development. Today, we will be discussing a crucial data visualization technique: setting the Y-axis to logarithmic scale in Matlab.

Matlab represents data in two dimensions by drawing plots. Sometimes, one of the axes represents values that progress exponentially. In such cases, rather than using a linear scale, it makes more sense to use a logarithmic scale to make the data more readable and insights from it more discernible.

Theory Lodged Behind Logarithmic Scale

Importance of Logarithmic Scale

The logarithmic scale is a method of data representation used when there is a large range of quantities. Real world phenomena spanning multiple orders of magnitude frequently benefit from a logarithmic representation. The advantage of using a logarithmic scale lies in its ability to handle a wide data range in a compact manner, converting exponential trends into linear ones.

The ‘set’ Function in Matlab

In Matlab, the ‘set’ function is a versatile and important function. It allows us to modify properties of a wide range of handles. One particular application of ‘set’ is in the context of plots, where it provides control over numerous properties, including axis scale.

Solution to setting Y-axis as Logarithmic Scale in Matlab

Here’s how to set the ‘YScale’ property of your axes to ‘log’:

Y = logspace(0,1,100);
X = linspace(0,10,100);
plot(X,Y);
set(gca, 'YScale', 'log');

This code begins by creating a logarithmic space array and a linear space array for the Y and X values, respectively. Followed by a simple plot command. Afterward, we use the ‘set’ command integrated with ‘gca’ to change the ‘YScale’ property to logarithmic.

Step-by-step Explanation of the Code

The above-mentioned code implements the log scaling in a quite straightforward way, and the explanation is as follows.

The ‘logspace’ and ‘linspace’ functions

The function ‘logspace’, generates a row vector with 100 points logarithmically spaced between 10^0 and 10^1.
In contrast, ‘linspace’ generates a linearly spaced vector for the X values.

The ‘plot’ function

The ‘plot’ function creates a 2D line plot of the X array against the Y array. At this point, the plot has been generated with a default linear ‘YScale’.

The ‘set’ function and ‘gca’

‘gca’ returns the handle to the current axes for the current figure. The ‘set’ function then assigns the ‘YScale’ property of these axes to ‘log’, transforming the Y-axis to a logarithmic scale.

Related Matlab Functions

– The ‘semilogy’ function: Matlab offers a function designed expressly for creating 2D plots with a logarithmic Y-axis and a linear X-axis: ‘semilogy’. It bypasses the need to use ‘set(gca, ‘YScale’, ‘log’)’.

– The ‘loglog’ function: The ‘loglog’ function is another related Matlab function. It creates a plot using logarithmic scales for both the X-axis and the Y-axis.

To wrap up, Matlab richly supports both linear and logarithmic data visualization. The ability to switch between these scales using ‘set’, ‘semilogy’, or ‘loglog’ according to the needs of the dataset enhances Matlab’s flexibility and power.