Quiver_by_plot
[toc]
1. Introduction
1.1 Features/Why I wrote this
-
More flexibility than the built-in function
quiver
.The arrows are generated by
plot
/patch
, which provides the possibility that everything can be adjusted. Here are some of the examples:-
The length of head (fixed length, or a ratio to the arrow length, etc.)
-
Angles between two edges of head.
-
Show/hide the head of arrows.
-
Show/hide the body of arrows.
-
Other properties in
plot
orpatch
. -
...
-
-
Colorful arrows adopted to current colormap
-
Support creating vector time series
-
"Perfect" arrows
1.2 Functions included
-
FUN_quiver_by_plotV2.m
Plot single color arrows by
plot
-
FUN_quiver_by_plotV2_mmap.m
This is same as
FUN_quiver_by_plotV2.m
but compatible withmmap
-
FUN_quiver_by_plotV2_cmap_patch.m
Plot colorful arrows based on
patch
. The color of arrows depends on colormap. -
FUN_quiver_by_plotV2_cmap_patch_mmap.m
This is same as
FUN_quiver_by_plotV2_cmap_patch.m
but compatible withmmap
-
FUN_quiver_by_plotV2_preset_cmap.m
[not recommended!] This is similar to
FUN_quiver_by_plotV2_cmap_patch
but the color is defined based on a fixed colormap, which must be specified
Limitation
To create a perfect arrow, the xlim
and ylim
must be defined explicitly and it should not be changed after calling this toolbox.
2. Install
You need to add this to the searching path of your Matlab environment before using them. The private
folder must be put in the same folder as FUN_quiver_by_plotV2*.m
. The subfolders (private
, doc
) should not be added to the searching path. It can be done by two ways:
If you have GUI access to Matlab :
Click "Home tab> Set Path". It will open a dialog for setting the path. Then, click "Add Folder...", add the root path of this package (the folder contains functions FUN_quiver_by_plotV2*.m
), then click "Save" near the bottom of the dialog.
If you are in a command line environment:
-
Method 1 (recommended):
addpath('/path/to/Quiver_by_plotV2/'); savepath
-
Method 2: Matlab will run
startup.m
during boot automatically if the file exists. Thus, you can addaddpath('/path/to/Quiver_by_plotV2/');
to thestartup.m
file and make sure that thestartup.m
is put in existing searching path. This provide more flexibility.
3. How to use this toolbox
FUN_quiver_by_plotV2.m
)
3.1 Plot arrows without colormap (FUN_quiver_by_plotV2
[h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v)
[h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v, vel_scale)
[h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v, vel_scale, ...)
INPUT:
x, y, u, v : input data
vel_scale [optional, default: 1 ]
0: auto scale
1: No scale, the original u/v will be used
otherwise: this scale will be applied to u and v.
Other parameters
Parameter | Default value | Notes |
---|---|---|
is_plot_head | true | show/hide head of arrows |
is_plot_body | true | show/hide body of arrows |
fill_head | false | If this is true, a filled triangle will be used as the head of each arrow. In this case, patch, instead of plot, is used to plot arrow heads. |
color | 'k' | color of arrows |
head_length_pixel | 0 | length of (the wing of) arrow head in units of pixel It shares the same unit with u and v. (Thus, the vel_scale will also be applied to head_length) 0 : it is set according to the gca (width & length in pixel). >0 : it is the absolute length of the arrow head -1~0: it is the percent of total vector length at each point. |
head_length_min_pixel | 0 | minimal length of arrow head length in units of pixel. |
head_angle | 15 | Angle between arrow head and arrow body2*head_angle is the angle between the two wings of the arrow head. |
is_correct_angle | false | This is for vector time series and some special cases. |
is_correct_angle_by_edit_v | false | |
head_style | 1 | Head style. See |
interval | 1 | interval |
interval_x | interval | interval for the first dim (usually x) |
interval_y | interval | interval for the second dim (usually y) |
is_plot_via_arrayfun | false | Call plot via arrayfun . This is useful if you want to change properties of a subsample of arrows.false: The returned handles h1 & h2 are 1 x 1 matrix (one for array body and one for arrow head) true: The returned handles h1 & h2 are [m x 1] matrix (one for array body and one for arrow head) Note: this does not support colorful plots yet. |
gca_pos_now | [] | By default, FUN_quiver_by_plotV2 will get it by calling plotboxpos . However, this costs a lot of time in repeating hundreds of plots with the same configuration. Providing this as an input variable could save some time. |
.... [varargin] | .... | Other parameters (e.g., 'linewidth') applicable to plot for regular plots or patch for colorful arrows. |
Parameters not recommended
Parameter | Default value | Notes |
---|---|---|
head_length | 0 | length of (the wing of) arrow head in the same unit as x-axis It shares the same unit with u and v. (Thus, the vel_scale will also be applied to head_length) 0 : it is set according to the gca (width & length in pixel). >0 : it is the absolute length of the arrow head -1~0: it is the percent of total vector length at each point. |
head_length_min | 0 | minimal length of arrow head |
Output
- h1: handle array for arrow body
- h2: handle array for arrow head
- uu [ 3 x N ]: x coordinate for arrow body, the 3 values in each col are [ x_origin; x_head; Nan]
- vv [ 3 x N ]: y coordinate for arrow body, the 3 values in each col are [ y_origin; y_head; Nan]
- hu [ 4 x N ]: x coordinate for arrow head, the 4 values in each col are [ x_head_wing1, x_head_center, x_head_wing2; Nan]
- hv [ 4 x N ]: y coordinate for arrow head, the 4 values in each col are [ y_head_wing1, y_head_center, y_head_wing2; Nan]
you can re-plot the arrows by uu,vv hu, hv:
plot( uu(:), vv(:) ); % plot arrow body
hold on
plot( hu(:), hv(:) ); % plot arrow head
Demos
Data used in this demo is generated by the following codes
x = -1:0.2:1;
y = -1:0.2:1;
[X,Y] = meshgrid(x,y);
X=X';
Y=Y';
theta = atan2d(Y,X);
r = sqrt( X.^2 + Y.^2);
u = sind( theta ) .* r / 100;
v = -cosd( theta ) .* r / 100;
x = x*10 - 75;
y = y*10 + 35;
This is also available here: Data_demo_1.mat.
Demo - plot arrows.
figure
xlim([-88 -62]);
ylim([22 48]);
FUN_quiver_by_plotV2( x, y, u, v, 0 )
title('Example 3.1: FUN_quiver_by_plotV2','Interpreter','none');
FUN_easy_export_fig('Example_3.1.jpg','-m2');
Demo - set absolute scale
vel_scale1 = 200;
vel_scale2 = 300;
figure
xlim([-88 -62]);
ylim([22 48]);
hold on
hd1 = FUN_quiver_by_plotV2( x, y, u, v, vel_scale1, 'color','m' );
hd2 = FUN_quiver_by_plotV2( x, y, u, v, vel_scale2, 'color','k' );
lid = legend( [hd1, hd2], 'scale=200', 'scale=300');
set(lid,'Interpreter','none');
box on
title('Example 1.2 "scale"');
Demo - set head length in pixel (parameter: 'head_length_pixel').
head_length1 = 20;
head_length2 = 10;
figure
xlim([-88 -62]);
ylim([22 48]);
hold on
hd1 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'head_length_pixel', head_length1, 'color','m' );
hd2 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'head_length_pixel', head_length2, 'color','k' );
lid = legend( [hd1, hd2], 'head_length_pixel=20', 'head_length_pixel=10');
set(lid,'Interpreter','none');
box on
title('Example 1.3: "head_length (positive)"','Interpreter','none');
head_length1 = -0.6;
head_length2 = -0.3;
figure
xlim([-88 -62]);
ylim([22 48]);
hold on
hd1 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'head_length_pixel', head_length1, 'color','m' );
hd2 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'head_length_pixel', head_length2, 'color','k' );
lid = legend( [hd1, hd2], 'head_length_pixel=-0.6', 'head_length_pixel=-0.3');
set(lid,'Interpreter','none');
box on
title('Example 1.3: "head_length (negative)"','Interpreter','none');
Demo - set head angle (parameter: 'head_angle').
head_angle1 = 20;
head_angle2 = 40;
figure
xlim([-88 -62]);
ylim([22 48]);
hold on
hd1 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'head_angle', head_angle1, 'color','m' );
hd2 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'head_angle', head_angle2, 'color','k' );
lid = legend( [hd1, hd2], 'head_angle=20', 'head_angle=40');
set(lid,'Interpreter','none');
box on
title('Example 1.4: "head_angle"','Interpreter','none');
Demo - hide arrow head (parameter: 'is_plot_head').
figure
xlim([-88 -62]);
ylim([22 48]);
hold on
hd1 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'is_plot_head', false );
box on
title('Example 1.5: "is_plot_head=false"','Interpreter','none');
Demo - hide arrow body (parameter: 'is_plot_body').
figure
xlim([-88 -62]);
ylim([22 48]);
hold on
hd1 = FUN_quiver_by_plotV2( x, y, u, v, 0, 'is_plot_body', false, 'head_length_pixel', 30, 'color','k' );
box on
title({'Example 1.6: "is_plot_body=false"','In this case, length of the arrow head must be','provided in parameter "head_length"'},'Interpreter','none');
Demo - perfect arrow head
figure
xlim([-0.2 1]*0.4);
ylim([-0.2 1]*1);
hold on
% this toolbox
hd1 = FUN_quiver_by_plotV2( 0, 0, 5, 5,0.050 );
% built-in matlab function
hd2 = quiver(0, 0, 5, 5 , 0.05, 'color','r', 'AutoScale', 'off','MaxHeadSize',15);
lid = legend( [hd1, hd2], 'FUN_quiver_by_plotV2', 'quiver');
set(lid,'Interpreter','none');
box on
title('Example 1.8: a "perfect" arrow','Interpreter','none');
FUN_quiver_by_plotV2_cmap_patch
)
3.2 Plot colorful arrows ([h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v)
[h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v, vel_scale)
[h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v, vel_scale, 'zval', zval)
[h1,h2, uu, vv, hu, hv] = FUN_quiver_by_plotV2( x, y, u, v, vel_scale, 'zval', zval, ...)
INPUT
- paramter 'zval' is used to determine the color. By default,
zval = sqrt( u.^2 + v.^2)
. - Other parameters are identical to
FUN_quiver_by_plotV2
.
output
- Identical to
FUN_quiver_by_plotV2
.
Demo
Demo - a simple case
In this case, the color is defined by the length of arrows, which is usually the magnitude of velocities.
%% prepare data
x = 1:40;
y = 1:30;
[X,Y] = meshgrid(x,y);
X=X';
Y=Y';
u = sin( 2*pi/30 .* X );
v = cos( 2*pi/30 .* Y );
% plot
figure
arrow_scale = 0; % 0: the scale is determined by the script automatically.
FUN_quiver_by_plotV2_cmap_patch( x, y, u, v, arrow_scale );
grid on
box on
xlabel('x');
ylabel('y');
colorbar
title({'Example 1: a simple case', 'Color is defined by the magnitude of arrows'});
Demo - the color is defined by a given matrix
In this example, the arrow color is defined in parameter zval
.
%% prepare data
x = 1:40;
y = 1:30;
[X,Y] = meshgrid(x,y);
X=X';
Y=Y';
u = sin( 2*pi/30 .* X );
v = cos( 2*pi/30 .* Y );
%% plot
figure
xlim([1 41]);
ylim([1 31]);
arrow_scale = 0; %auto
value_for_color = sqrt(X.^2+Y.^2);
FUN_quiver_by_plotV2_cmap_patch( x, y, u, v, arrow_scale, 'zval', value_for_color );
grid on
box on
xlabel('x');
ylabel('y');
colorbar
title({'Example 2.2: Color is defined by parameter "zval"'});
3.3 Work with mmap
FUN_quiver_by_plotV2_mmap
)
3.3.1 Simple arrows (Inputs are identical to FUN_quiver_by_plotV2
.
It is recommended to call m_grid before FUN_quiver_by_plotV2_mmap
%% prepare data
x = -1:0.2:1;
y = -1:0.2:1;
[X,Y] = meshgrid(x,y);
X=X';
Y=Y';
theta = atan2d(Y,X);
r = sqrt( X.^2 + Y.^2);
u = sind( theta ) .* r / 100;
v = -cosd( theta ) .* r / 100;
x = x*10 - 75;
y = y*10 + 35;
%% plot
figure
hold on
m_proj('lambert', 'lon', [-88 -62], 'lat', [22 48] );
m_grid;
hd1 = FUN_quiver_by_plotV2_mmap( x, y, u, v, 0 );
m_coast('color','b')
title({'Example 3.1: Arrows on m_map'},'Interpreter','none');
FUN_quiver_by_plotV2_cmap_patch_mmap
)
3.3.2 Colorful arrows (Inputs are identical to FUN_quiver_by_plotV2_cmap_patch
.
It is recommended to call m_grid before FUN_quiver_by_plotV2_mmap
%% prepare data
x = -1:0.2:1;
y = -1:0.2:1;
[X,Y] = meshgrid(x,y);
X=X';
Y=Y';
theta = atan2d(Y,X);
r = sqrt( X.^2 + Y.^2);
u = sind( theta ) .* r / 100;
v = -cosd( theta ) .* r / 100;
x = x*10 - 75;
y = y*10 + 35;
%% plot
figure
hold on
m_proj('lambert', 'lon', [-88 -62], 'lat', [22 48] );
m_grid
FUN_quiver_by_plotV2_cmap_patch_mmap( x, y, u, v, 0 );
m_coast('color','b')
colorbar
title({'Example 3.2: Colorful arrows on m_map'},'Interpreter','none');
3.4. Vector Time Series
To plot vector time series, plot set is_correct_angle
to true
.
%% prepare data
x = 0:5:270;
u = cosd(x);
v = sind(x);
%% Example 1.1 A simple case
figure('position',[ 100 100 980 300])
hold on
% please always set xlim and ylim first
xlim([min(x) max(x)]);
ylim([-1.2 1.2])
vel_plot_scale = 1; % arrow sacle
% plot arrows
% 'is_correct_angle' is set to true to plot arrows according to its real
% direction, ignorning the ratio between x & y axis.
FUN_quiver_by_plotV2( x, zeros(size(x)), u, v, vel_plot_scale, 'is_correct_angle', true, 'is_plot_head', false);
box on
plot( x, zeros(size(x)), '-b');
title('Example: Vector time series');
3.5 Arrow style
-
default style (
head_style=1
) -
The head_style=2 can be further tuned by setting parameter
head_length_2
4. Acknowledgements
Matlab script plotboxpos
, which is available from https://github.com/kakearney/plotboxpos-pkg, is adopted to calculate the accurate axis ratio.
Zitieren als
L Chi (2024). Quiver_by_plot (https://github.com/HappySpring/Quiver_by_plot/releases/tag/v3.01), GitHub. Abgerufen .
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Version | Veröffentlicht | Versionshinweise | |
---|---|---|---|
3.01 | See release notes for this release on GitHub: https://github.com/HappySpring/Quiver_by_plot/releases/tag/v3.01 |
||
3.00 |