Frankkweb Word Format Matlab

8/2/2019 Frankkweb Word Format Matlab

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How to Format a Matlab Graph 1

Jeffrey Donell

The Woodruff School of Mechanical Engineering

HOW FORMAT A MATLAB GRAPH

Jeffrey DonnellThe George W. Woodruff School of Mechanical Engineering

The Georgia Institute of TechnologyAtlanta, GA 30332

SummaryThis document reviews the steps that a beginner should take in order to adjust a Matlab plot for display in a printdocument. Specifically, this document explains:

1) How to scale the plot to frame the data.

2) How to display and adjust the legend.

3) How to adjust the display of data points and related model or uncertainty lines.

4) How to export a finished plot in various Windows-friendly formats.


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Experimental results are often represented graphically, and your graphs must package information clearly, sim-

ply and specifically. You achieve these goals byformatting your graphs or plots. Plotting tools, such as those in

Excel and in Matlab, can give you great control over your information display, but they do not do all the work for

you. After you generate a plot in Matlab, you must adjust that plots formatting in order to produce a good dis-

play. This document shows you the basic steps for adjusting a Matlab plots format, and it outlines the principles

you should follow in making your format adjustments.

We will show you how to adjust the graph shown below. Your experimental project results might be displayed in

a Matlab plot that looks like this:

This is a perfectly acceptable chart. It is rich with information, and it provides no distractions from that informa-

tion. Every line and axis has a specific label, with units easily visible. On the plot, paired/related data sets are

visually related by the coordinated weights and patterns of the lines. There is no distracting non-data information

on the plot.


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Your goal is to produce a clear and simple chart like that shown here. But when you prepare a plot using Mat-

labs defaults, your graph might look more like this:

In order to obtain the desired display, you need re-format this chart by hand. This document walks you through

the process of scaling the axes, adjusting the legends appearance and placement, and setting the appearance of

the data markers and model lines themselves.

General: Scale the Axes to Frame the Data

The first task in formatting a plot is to adjust the X- and Y-axes. As you do this, remember that your data should

dominate the plot. Consequently, you should adjust the axis scales to eliminate blank space on the sides, top and

bottom of the plot.

HOWEVER: When you adjust the axis scales, you will probably introduce distorting offsets from the origin

location on the chart; it is your job to determine whether these distortions are trivial or significant. You must

always be able to characterize and explain such distortions, and your specific decisions about axis scales should

take the problem of distortion into account. In this example, we assume that the problem of distortion is trivial,

and we will scale the axes to frame the data very tightly.


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1) Scale the Chart

In Matlab, Plot Editing must be enabled before you do anything. To do this, pull down the Tools menu and

select Enable Plot Editing:

Now Matlab will let you adjust the display.


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In order to scale the axes, you must preselect an axis by clicking on the plot. Then re-open the Tools pull-down

menu and select Axes Properties in order to begin editing:

With this selection made, the largeEdit Axes Properties dialog box opens, allowing you to adjust the maximum

and minimum values for each axis.


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Here, the Y-axis has been scaled to frame the data, y-grids have been removed and an axis label has been applied:

The changes have already been applied and are shown on the plot.


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Now the X-axis will be adjusted as well:

Unnecessary grids have been cleared, the axes are labeled and the data fills the whole of the chart.


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2) Adjust the Legend

The tools menu is pulled down and the Legend is selected for display:

In this image, the legend has already been selected, and it is shown in its default position at the top right corner of

the plot.

Matlab places the legend directly on the plot. In most cases, such placement saves space and allows for a larger

display; but this legend obscures some of the data. It must be moved to an empty region of the plot and it must be

edited to display the correct descriptions of the data series.


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To move the legend, simply select and drag it with the mouse. Then select and type over each entry to provide

specific descriptors for the different data series.


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The legend box resizes to accommodate long entries. The fully edited legend is shown below:


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3) Adjust the Display of Data Lines

To adjust the data display, each line must be selected and edited individually.

The principles for representing data sets are these:

--A single data set can be represented with markers only.

--When two or more data sets are presented, the markers are connected with straight (not smoothed) lines. Mark-

ers and lines must be visually distinct in order that the data sets can be distinguished.--When a model is graphed, it is represented as a smoothed line without markers.

--When several models are shown, they can be grouped or distinguished through use of similar (or distinct) line

patterns and weights.

The student must determine which sets of data or of models are to be grouped, and the student must be able to

explain any grouping decisions that s/he reaches.

Here, we seek to distinguish line types so that we can reproduce this graph in black and white. To do this, we

must adjust the line weights and line patterns--dots and dashes and the like. We must also be certain that our data

points are represented appropriately.

The Model - Umodel line--the bottom line of this chart--is adjusted first:

We select this line by double-clicking, and the Edit Line Properties dialog opens. This box offers a submenu

allowing you to specify the lines color, size and style. For this display, we will set line Color to black.

Matlabs default line width is too narrow for many printers to manage successfully; we will increase the 0.1

(point) line Size to 1.0. We select a line Style with wide dashes.

These selections, and the resulting graph, are shown in the following display:


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The other uncertainty bands are formatted in the same fashion. The -Umodel bands use the same dash pattern,

while the -Udata use a distinct, but coordinated dash pattern, as shown in the next illustration:


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Here, with the data series Lit formatted as a medium-width, solid line, the graph is fully formatted.


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4) Options for Exporting a Finished Plot

This finished graph can be copied directly for use in Word or PowerPoint, or from the File menu, it can be

exported in a variety of windows-friendly file formats.

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