Matrix of scatter plots by group (2024)

Input data, specified as an n-by-p numeric matrix, datetime array, or duration array. gplotmatrix creates a matrix of plots using the columns of X. If you do not specify an additional input matrix Y, then gplotmatrix creates a p-by-p matrix of plots. The off-diagonal plots are scatter plots, and the diagonal plots depend on the value of dispopt. In each scatter plot, gplotmatrix plots one column of X against another column of X. The points in the scatter plots are grouped according to group.

If you specify Y, then gplotmatrix creates a q-by-p matrix of scatter plots using the p columns of X and the q columns of Y.

Data Types: single | double | datetime | duration

Input data, specified as an n-by-q numeric matrix, datetime array, or duration array. gplotmatrix creates a q-by-p matrix of scatter plots using the p columns of X and the q columns of Y. For each column of the plot matrix, the x-axis values of the scatter plots are the same as the values in the corresponding column of X. Similarly, for each row of the plot matrix, the y-axis values of the scatter plots are the same as the values in the corresponding column of Y. The points in the scatter plots are grouped according to group.

X and Y must have the same number of rows.

Data Types: single | double | datetime | duration

Grouping variable, specified as a categorical vector, numeric vector, logical vector, character array, string array, or cell array of character vectors. Alternatively, group can be a cell array containing several grouping variables (such as {g1 g2 g3}), in which case observations are in the same group if they have common values of all grouping variables. In any case, group must have the same number of rows as X. Points in the same group appear on the graph with the same marker color, symbol, and size.

Example: categorical({'blue','red','yellow','blue','yellow','red','red','yellow','blue','red'})

Example: {Smoker,Gender} where Smoker and Gender are grouping variables

Data Types: categorical | single | double | logical | char | string | cell

Marker colors, specified as a character vector or string scalar of short color names or a matrix of RGB triplets.

For a custom color, specify a matrix of RGB triplets. An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

Alternatively, you can specify some common colors by name. This table lists the named color options and the equivalent RGB triplets

This table lists the RGB triplet color codes for the default colors used by MATLAB in many types of plots.

The default value for clr is the matrix of RGB triplets containing the MATLAB default colors.

If you do not specify enough colors for all unique groups in g, then gplotmatrix cycles through the specified values in clr. If you use default values when the number of unique groups exceeds the number of default colors (7), then gplotmatrix cycles through the default values, as needed.

Example: 'rgb'

Example: [0 0 1; 0 0 0]

Data Types: char | string | single | double

Marker symbols, specified as a character vector or string scalar.

You can choose among these marker options.

By default, gplotmatrix assigns '.' as the marker symbol for each group. When the total number of groups exceeds the number of specified symbols, gplotmatrix cycles through the specified symbols.

Example: 'x'

Example: 'xo+'

Data Types: char | string

Marker sizes, specified as a positive numeric vector. The default value is determined by the number of observations. When the total number of groups exceeds the number of specified sizes, gplotmatrix cycles through the specified sizes.

Example: [6 12]

Data Types: single | double

Display options for the diagonal plots in the plot matrix, specified as 'stairs', 'hist','grpbars', 'none', or 'variable'. This table describes the different display options.

The default is 'stairs' when group contains more than one group. Otherwise, gplotmatrix displays a single histogram in each diagonal plot.

To generate the histograms, gplotmatrix uses the 'pdf' type of normalization for numeric data and the 'count' type of normalization for datetime and duration data. (See the 'Normalization' name-value pair argument of histogram.) Note that the y-axis tick mark labels do not apply to the histograms. Use data tips to see the correct histogram values.

X column names, specified as a character array, string array, or cell array of character vectors. xnam must contain one name for each column of X.

Example: {'Sepal Length','Sepal Width','Petal Length','Petal Width'}

Data Types: char | string | cell

Y column names, specified as a character array, string array, or cell array of character vectors. ynam must contain one name for each column of Y.

Example: {'Diastolic','Systolic'}

Data Types: char | string | cell

• p-by-p-by-k array of Line and Histogram objects if you do not specify Y

• q-by-p-by-k array of Line objects if you specify both X and Y