Introduction
Sometimes when the colorbar is drawn, when the value range of the data is set, the representation method beyond the two ends of the range sometimes needs to be described by adding sharp corners. The colorbar function of Matlab does not have this function. The colorbar can increase sharp corners by adding function functions.
method 1
The code comes from the Matlab forum: https://www.mathworks.com/matlabcentral/fileexchange/52515-cbarrow-pointy-ends-for-colorbars
Function code
function h = cbarrow(options)
%% cbarrow documentation
% The cbarrow function places triangle-shaped endmembers on colorbars to
% indicate that data values exist beyond the extents of the values shown in
% the colorbar.
%
% This function works by creating a set of axes atop the current figure and
% placing patch objects on the new axes. Thus, editing a figure after
% calling cbarrow may cause some glitches. Therefore, it is recommended to call
% cbarrow last when creating plots.
%
%% Syntax
%
% cbarrow
% cbarrow(Direction)
% cbarrow('delete')
% h = cbarrow(...)
%
%% Description
%
% cbarrow places triangle-shaped endmembers on both ends of the current
% colorbar.
%
% cbarrow(Direction) specifies a single direction to place a colorbar end
% arrow. Direction can be 'up', 'down', 'right', or 'left'.
%
% cbarrow('delete') deletes previously-created cbarrow objects.
%
% h = cbarrow(...) returns a handle of the axes on which cbarrow
% objects are created.
%
%% Example 1: Both directions
%
% surf(peaks)
% axis tight
% colorbar
% caxis([0 3])
% cbarrow
%
%% Example 2: One direction
%
% surf(peaks)
% axis tight
% colorbar('southoutside')
% colormap(brewermap(256,'*RdBu'))
% caxis([-7 7])
% cbarrow('right')
%
%% Known issues
% This function only works once per figure. If you have multiple subplots,
% you can only use it once, and you'll have to call cbarrow last. Also,
% editing plots after calling cbarrow can sometimes be a bit glitchy.
%
%% Author Info
% The newcolorbar function was written by Chad A. Greene of the
% University of Texas at Austin's Institute for Geophysics (UTIG), August 2015.
% Updated June 2016 to fix a bug in cbarrow('down'), thanks to Aodat for pointing this out.
% http://www.chadagreene.com.
%
% See also caxis and colorbar.
%% Error checks:
assert(verLessThan('matlab','8.4.0')==0,'Sorry, the cbarrow function requires Matlab R2014b or later.')
narginchk(0,1)
%% Guess which arrows to create based on current colorbar orientation:
% Find handles of all colorbars in current figure:
hcb = findobj(gcf,'Type','Colorbar');
% If no colorbars exist in current figure, create a new one:
if isempty(hcb)
cb = colorbar;
else
% Otherwise, use the most recent colorbar in the list:
cb = hcb(1);
end
cbpos = cb.Position;
ax1 = gca;
ax1pos = get(ax1,'OuterPosition');
% If the colorbar is wider than it is tall, make left and right arrows:
if cbpos(4)<cbpos(3)
makerightarrow = true;
makeleftarrow = true;
makeuparrow = false;
makedownarrow = false;
else
% Otherwise make up and down arrows:
makerightarrow = false;
makeleftarrow = false;
makeuparrow = true;
makedownarrow = true;
end
%% Override automatic arrow selection if user requested a specific arrow:
if nargin>0
switch lower(options)
case {
'del','delete'}
try
h_cbarrow = findobj(gcf,'tag','cbarrow');
delete(h_cbarrow);
end
return
case {
'r','right'}
makerightarrow = true;
makeleftarrow = false;
case {
'l','left'}
makeleftarrow = true;
makerightarrow = false;
case {
'u','up'}
makeuparrow = true;
makedownarrow = false;
case {
'd','down'}
makedownarrow = true;
makeuparrow = false;
otherwise
error('Invalid input in cbarrow. Must be ''up'',''down'', ''left'', ''right'', ''delete'', or no inputs at all for automatic cbarrowing.')
end
end
%% Shrink position of the colorbar to allow room for arrows:
if makerightarrow
cbpos = cbpos + [0 0 -cbpos(4)*sqrt(2)/2 0];
cb.Position = cbpos;
end
if makeleftarrow
cbpos = cbpos + [cbpos(4)*sqrt(2)/2 0 -cbpos(4)*sqrt(2)/2 0];
cb.Position = cbpos;
end
if makeuparrow
cbpos = cbpos + [0 0 0 -cbpos(3)*sqrt(2)/2];
cb.Position = cbpos;
end
if makedownarrow
cbpos = cbpos + [0 cbpos(3)*sqrt(2)/2 0 -cbpos(3)*sqrt(2)/2];
cb.Position = cbpos;
end
%% Create triangle arrows as patch objects in new axes:
% Get colormap so we know what color to make the triangles:
cm = colormap;
% Create background axes on which to plot patch objects:
h = axes('position',[0 0 1 1],'tag','cbarrow');
hold on
% Plot arrows:
if makerightarrow
rightarrowx = (cbpos(1)+cbpos(3)) + [0 cbpos(4)*sqrt(2)/2 0 0];
rightarrowy = cbpos(2) + [0 cbpos(4)/2 cbpos(4) 0];
hr = patch(rightarrowx,rightarrowy,cm(end,:),'EdgeColor',cm(end,:));
end
if makeleftarrow
leftarrowx = cbpos(1) + [0 -cbpos(4)*sqrt(2)/2 0 0];
leftarrowy = cbpos(2) + [0 cbpos(4)/2 cbpos(4) 0];
hl = patch(leftarrowx,leftarrowy,cm(1,:),'EdgeColor',cm(1,:));
end
if makeuparrow
uparrowx = cbpos(1) + [0 cbpos(3) cbpos(3)/2 0];
uparrowy = cbpos(2)+cbpos(4) + [0 0 cbpos(3)*sqrt(2)/2 0];
hu = patch(uparrowx,uparrowy,cm(end,:),'EdgeColor',cm(end,:));
end
if makedownarrow
downarrowx = cbpos(1) + [0 cbpos(3) cbpos(3)/2 0];
downarrowy = cbpos(2) + [0 0 -cbpos(3)*sqrt(2)/2 0];
hd = patch(downarrowx,downarrowy,cm(1,:),'EdgeColor',cm(1,:));
end
%% Change edge colors:
if strcmpi(cb.Box,'on')
% Get starting color and linewidth of colorbar box:
linecolor = cb.Color;
linewidth = cb.LineWidth;
% Turn off colorbar box and we'll create a new one:
cb.Box = 'off';
% Edge line for left and right arrows:
if all([makerightarrow makeleftarrow])
line(cbpos(1) +[0 cbpos(3) cbpos(3)+cbpos(4)*sqrt(2)/2 cbpos(3) 0 -cbpos(4)*sqrt(2)/2 0],...
cbpos(2) + [0 0 cbpos(4)/2 cbpos(4) cbpos(4) cbpos(4)/2 0],...
'color',linecolor,'LineWidth',linewidth)
end
% Edge line for right only:
if all([makerightarrow ~makeleftarrow])
line(cbpos(1) +[0 cbpos(3) cbpos(3)+cbpos(4)*sqrt(2)/2 cbpos(3) 0 0],...
cbpos(2) + [0 0 cbpos(4)/2 cbpos(4) cbpos(4) 0],...
'color',linecolor,'LineWidth',linewidth)
end
% Edge line for left arrow only:
if all([~makerightarrow makeleftarrow])
line(cbpos(1) +[0 cbpos(3) cbpos(3) 0 -cbpos(4)*sqrt(2)/2 0],...
cbpos(2) + [0 0 cbpos(4) cbpos(4) cbpos(4)/2 0],...
'color',linecolor,'LineWidth',linewidth)
end
% Edge line for up and down arrows:
if all([makeuparrow makedownarrow])
line(cbpos(1) +[0 0 cbpos(3)/2 cbpos(3) cbpos(3) cbpos(3)/2 0],...
cbpos(2) + [0 cbpos(4) cbpos(4)+cbpos(3)*sqrt(2)/2 cbpos(4) 0 -cbpos(3)*sqrt(2)/2 0],...
'color',linecolor,'LineWidth',linewidth)
end
% Edge line for up arrow only:
if all([makeuparrow ~makedownarrow])
line(cbpos(1) +[0 0 cbpos(3)/2 cbpos(3) cbpos(3) 0],...
cbpos(2) + [0 cbpos(4) cbpos(4)+cbpos(3)*sqrt(2)/2 cbpos(4) 0 0],...
'color',linecolor,'LineWidth',linewidth)
end
% Edge line for down arrow only:
if all([~makeuparrow makedownarrow])
line(cbpos(1) +[0 0 cbpos(3) cbpos(3) cbpos(3)/2 0],...
cbpos(2) + [0 cbpos(4) cbpos(4) 0 -cbpos(3)*sqrt(2)/2 0],...
'color',linecolor,'LineWidth',linewidth)
end
end
%% Clean up:
axis off
axis([0 1 0 1])
% If original current axes were resized, unresize them:
set(ax1,'OuterPosition',ax1pos)
switch lower(cb.Location)
case {
'south','east','north','west'}
% Bring our arrow patch object axes to the front if the colorbar is inside the current axes:
axes(h)
otherwise
% Bring user's data axes to the front:
axes(ax1)
end
% Delete output if user did not request it:
if nargout==0
clear h
end
end
usage
surf(peaks)
axis tight
colorbar
caxis([0 3])
cbarrow
effect
Method 2
Need to install m_map toolbox. This method needs to set the position of the colorbar, which is not very easy to grasp, but the colorbar effect made is still very good, and you can also set a non-linear label. The data in the chart column needs to be prepared by yourself.
Code
clf;
m_proj('miller','lat',82);
m_pcolor(m_lon,m_lat,m_sps);
[CS,CH]=m_contourf(m_lon,m_lat,m_sps,[0.1:0.1:0.5 1:0.5:1.5],'edgecolor','none');
m_coast('color',[0 0 0], 'linewidth', 1.2);
m_grid('tickdir','out','linewi',2);
ax = m_contfbar([.3 .7],.05,CS,CH);
% 如果bar是竖直的，这里是ytick和yticklabel
ax.XTick = [0.1 0.5 1:0.5:1.5];
ax.XTickLabel = [0.1 0.5 1:0.5:1.5];
colormap(flipud(m_colmap('Blues')))
% close all;
