Detailed explanation of MATLAB drawing function fplot

Detailed explanation of MATLAB drawing function fplot
1. Basic syntax of fplot
Unlike plot, fplot is mainly used to directly draw function curves according to the function expression and the interval to which the independent variables belong.Therefore, when the function expression is known, it is relatively simple to use fplot to draw the function curve.
Its basic syntax is as follows:

1) fplot( f, xinterval, s )

Where f is the expression of the independent variable in the function, xinterval is the value range of the independent variable, and s represents the attribute of the primitive, which is similar to the primitive attribute in the plot.When xinterval is default, the default interval of the argument is [-5, 5].

2) fplot( fx, fy, tinterval, s )

This form is mainly used to draw function curves represented by parametric equations.Where fx and fy represent the expressions of x and y with respect to parameter t, respectively, tinterval is the value range of parameter t, and s represents the attribute of the primitive.

3) fplot( @(var) f(var), xinterval, s )

Where @(var) is to declare var as an independent variable (the identifier can be given as needed), f(var) is a specific function expression, xinterval is the value range of the independent variable, and s represents the value of the primitiveAttributes.

4) fplot( @(t)fx(t), @(t) fy(t), tinterval, s )

Where @(t) is to declare t as a parameter (the identifier can be given as needed), fx(t) and fy(t) are the expressions of the abscissa and ordinate of the specific parameter equation, and tinterval is the parameterThe value range of t, and s represents the attribute of the primitive.
Note: Usage 1) and 2) will have a warning in the new version.3) and 4) are standard usage in the new version.
Second, the specific example
Example 1. Draw y=sin(x) curve graph.

% sample code (1)clear allclcfplot( 'sin(x)' ) % only function expressions are given

%run result

% sample code (2)clear allclcfplot( 'sin(x)',[ -pi, pi ], 'ro' )xlabel( 'x' );ylabel( 'sin(x)' );

%run result

% sample code (3)clear allclcfplot( @(x)sin(x),[ -pi, pi ] )xlabel( 'x' );ylabel( 'sin(x)' );

%Running results

Example 2. In the sameOne window draws sine and cosine curves in one cycle

% sample codeclear allclcfplot( @(x)sin(x),[ -pi, pi ], 'r-.' )hold onfplot( @(x)cos(x),[ -pi, pi ], 'b--' )xlabel( 'x' );ylabel( 'y' );legend( 'y=sin(x)', 'y=cos(x)' );

%run result

Example 3. Drawing a unit circle

% sample codeclear allclcfplot( @(t)sin(t), @(t)cos(t),[ -pi, pi ] ) % solid line unit circlehold onfplot( @(t)sin(t), @(t)cos(t),[ -pi, pi ], 'ro' ) % unit circle scatterplotxlabel( 'x' );ylabel( 'y' );title( 'Unit Circle' );axis equalaxis( [ -1.5, 1.5, -1.5, 1.5 ] );

%run result

Example 4. Plot piecewise function curve

% sample codeclear allclcfplot( @(x)(7-x).^2/4,[1, 5 ], 'r' )hold onfplot( @(x)x-4,[5, 10 ], 'r' )fplot( @(x)16-x,[10, 15 ], 'r' )fplot( @(x)(x-13).^2/4,[15, 19 ], 'r' )xlabel( 'x' );ylabel( 'y' );title( 'Piecewise Function Curve' );axis( [ 0, 20, 0, 10 ] );

%run result