【混淆矩阵】matlab画混淆矩阵

主要借鉴此博客代码：http://blog.csdn.net/sherry_gp/article/details/50560003

但是这个博主的代码达不到我想要的效果，所以修改了一下

我想要实现的效果是：给定一列的预测标签，以及这一列标签的哪一部分理应属于哪一部分标签。

此代码实现的功能是：

给定条件：给定预测标签为A=[1 2 1 1 2 2 3 2 3 3 3 3 4 4 1 4];

                   每一类标签总数为num=[4 4 4 4]（这里可以看出总共四类标签，每类标签的样本数为4）;

                   四个类名：第一类、第二类、第三类、第四类

原始标签为：A=[1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4];

实现结果：每一类预测的准确率【也就是看A与B的差别在哪里】

代码【我修改的是compute_confusion_matrix.m，其余和借鉴的博主提供的代码一样】：

rotateXLabels.m

function hh = rotateXLabels( ax, angle, varargin )
%rotateXLabels: rotate any xticklabels
%
% hh = rotateXLabels(ax,angle) rotates all XLabels on axes AX by an angle
% ANGLE (in degrees). Handles to the resulting text objects are returned
% in HH.
%
% hh = rotateXLabels(ax,angle,param,value,...) also allows one or more
% optional parameters to be specified. Possible parameters are:
% 'MaxStringLength' The maximum length of label to show (default inf)
%
% Examples:
% >> bar( hsv(5)+0.05 )
% >> days = {'Monday','Tuesday','Wednesday','Thursday','Friday'};
% >> set( gca(), 'XTickLabel', days )
% >> rotateXLabels( gca(), 45 )
%
% See also: GCA
% BAR

% Copyright 2006-2010 The MathWorks Ltd.
% $Revision: 52 $
% $Date: 2010-09-30 11:19:49 +0100 (Thu, 30 Sep 2010) $

error( nargchk( 2, inf, nargin ) );
if ~isnumeric( angle ) || ~isscalar( angle )
error( 'RotateXLabels:BadAngle', 'Parameter ANGLE must be a scalar angle in degrees' )
end
angle = mod( angle, 360 );

[maxStringLength] = parseInputs( varargin{:} );

% Get the existing label texts and clear them
[vals, labels] = findAndClearExistingLabels( ax, maxStringLength );

% Create the new label texts
h = createNewLabels( ax, vals, labels, angle );

% Reposition the axes itself to leave space for the new labels

repositionAxes( ax );

% If an X-label is present, move it too
repositionXLabel( ax );

% Store angle
setappdata( ax, 'RotateXLabelsAngle', angle );

% Only send outputs if requested
if nargout
hh = h;
end

%-------------------------------------------------------------------------%
function [maxStringLength] = parseInputs( varargin )
% Parse optional inputs
maxStringLength = inf;
if nargin > 0
params = varargin(1:2:end);
values = varargin(2:2:end);
if numel( params ) ~= numel( values )
error( 'RotateXLabels:BadSyntax', 'Optional arguments must be specified as parameter-value pairs.' );
end
if any( ~cellfun( 'isclass', params, 'char' ) )
error( 'RotateXLabels:BadSyntax', 'Optional argument names must be specified as strings.' );
end
for pp=1:numel( params )
switch upper( params{pp} )
case 'MAXSTRINGLENGTH'
maxStringLength = values{pp};

otherwise
error( 'RotateXLabels:BadParam', 'Optional parameter ''%s'' not recognised.', params{pp} );
end
end
end
end % parseInputs
%-------------------------------------------------------------------------%
function [vals,labels] = findAndClearExistingLabels( ax, maxStringLength )
% Get the current tick positions so that we can place our new labels
vals = get( ax, 'XTick' );

% Now determine the labels. We look first at for previously rotated labels
% since if there are some the actual labels will be empty.
ex = findall( ax, 'Tag', 'RotatedXTickLabel' );
if isempty( ex )
% Store the positions and labels
labels = get( ax, 'XTickLabel' );
if isempty( labels )
% No labels!
return
else
if ~iscell(labels)
labels = cellstr(labels);
end
end
% Clear existing labels so that xlabel is in the right position
set( ax, 'XTickLabel', {}, 'XTickMode', 'Manual' );
setappdata( ax, 'OriginalXTickLabels', labels );
else
% Labels have already been rotated, so capture them
labels = getappdata( ax, 'OriginalXTickLabels' );
delete(ex);
end
% Limit the length, if requested
if isfinite( maxStringLength )
for ll=1:numel( labels )
if length( labels{ll} ) > maxStringLength
labels{ll} = labels{ll}(1:maxStringLength);
end
end
end

end % findAndClearExistingLabels

%-------------------------------------------------------------------------%
function textLabels = createNewLabels( ax, vals, labels, angle )
% Work out the ticklabel positions
% ylim = get(ax,'YLim');
% y = ylim(1);
zlim = get(ax,'ZLim');
z = zlim(1);

% We want to work
% in normalised coords, but switch to normalised after setting
% position causes positions to be rounded to the nearest pixel.
% Instead we can do the calculation by hand.
xlim = get( ax, 'XLim' );
normVals = (vals-xlim(1))/(xlim(2)-xlim(1));
y = 0;

% Now create new text objects in similar positions.
textLabels = -1*ones( numel( vals ), 1 );
for ll=1:numel(vals)
textLabels(ll) = text( ...
'Units', 'Normalized', ...
'Position', [normVals(ll), y, z], ...
'String', labels{ll}, ...
'Parent', ax, ...
'Clipping', 'off', ...
'Rotation', angle, ...
'Tag', 'RotatedXTickLabel', ...
'UserData', vals(ll) );
end

% Now copy font properties into the texts
updateFont();

% Depending on the angle, we may need to change the alignment. We change
% alignments within 5 degrees of each 90 degree orientation.
if 0 <= angle && angle < 5
set( textLabels, 'HorizontalAlignment', 'Center', 'VerticalAlignment', 'Top' );
elseif 5 <= angle && angle < 85
set( textLabels, 'HorizontalAlignment', 'Right', 'VerticalAlignment', 'Top' );
elseif 85 <= angle && angle < 95
set( textLabels, 'HorizontalAlignment', 'Right', 'VerticalAlignment', 'Middle' );
elseif 95 <= angle && angle < 175
set( textLabels, 'HorizontalAlignment', 'Right', 'VerticalAlignment', 'Bottom' );
elseif 175 <= angle && angle < 185
set( textLabels, 'HorizontalAlignment', 'Center', 'VerticalAlignment', 'Bottom' );
elseif 185 <= angle && angle < 265
set( textLabels, 'HorizontalAlignment', 'Left', 'VerticalAlignment', 'Bottom' );
elseif 265 <= angle && angle < 275
set( textLabels, 'HorizontalAlignment', 'Left', 'VerticalAlignment', 'Middle' );
elseif 275 <= angle && angle < 355
set( textLabels, 'HorizontalAlignment', 'Left', 'VerticalAlignment', 'Top' );
else % 355-360
set( textLabels, 'HorizontalAlignment', 'Center', 'VerticalAlignment', 'Top' );
end
end % createNewLabels

%-------------------------------------------------------------------------%
function repositionAxes( ax )
% Reposition the axes so that there's room for the labels
% Note that we only do this if the OuterPosition is the thing being
% controlled
if ~strcmpi( get( ax, 'ActivePositionProperty' ), 'OuterPosition' )
return;
end

% Work out the maximum height required for the labels
textLabels = findall( ax, 'Tag', 'RotatedXTickLabel' );
maxHeight = 0;
for ii=1:numel(vals)
ext = get( textLabels(ii), 'Extent' );
if ext(4) > maxHeight
maxHeight = ext(4);
end
end

% Remove listeners while we mess around with things, otherwise we'll
% trigger redraws recursively
removeListeners( ax );

% Change to normalized units for the position calculation
oldUnits = get( ax, 'Units' );
set( ax, 'Units', 'Normalized' );

% Not sure why, but the extent seems to be proportional to the height of the axes.
% Correct that now.
set( ax, 'ActivePositionProperty', 'Position' );
pos = get( ax, 'Position' );
axesHeight = pos(4);
% Make sure we don't adjust away the axes entirely!
heightAdjust = min( (axesHeight*0.9), maxHeight*axesHeight );

% Move the axes
if isappdata( ax, 'OriginalAxesPosition' )
pos = getappdata( ax, 'OriginalAxesPosition' );
else
pos = get(ax,'Position');
setappdata( ax, 'OriginalAxesPosition', pos );
end
setappdata( ax, 'PreviousYLim', get( ax, 'YLim' ) );
set( ax, 'Position', pos+[0 heightAdjust 0 -heightAdjust] )
set( ax, 'Units', oldUnits );
set( ax, 'ActivePositionProperty', 'OuterPosition' );

% Make sure we find out if axes properties are changed
addListeners( ax );

end % repositionAxes

%-------------------------------------------------------------------------%
function repositionXLabel( ax )
% Try to work out where to put the xlabel

removeListeners( ax );
textLabels = findall( ax, 'Tag', 'RotatedXTickLabel' );
maxHeight = 0;
for ll=1:numel(vals)
ext = get( textLabels(ll), 'Extent' );
if ext(4) > maxHeight
maxHeight = ext(4);
end
end

% Use the new max extent to move the xlabel
xlab = get(ax,'XLabel');
set( xlab, 'Units', 'Normalized', 'Position', [0.5 -maxHeight 0] );
addListeners( ax );
end % repositionXLabel

%-------------------------------------------------------------------------%
function updateFont()
% Update the rotated text fonts when the axes font changes
properties = {
'FontName'
'FontSize'
'FontAngle'
'FontWeight'
'FontUnits'
};
propertyValues = get( ax, properties );
textLabels = findall( ax, 'Tag', 'RotatedXTickLabel' );
set( textLabels, properties, propertyValues );
end % updateFont

%-------------------------------------------------------------------------%
function onAxesFontChanged()
updateFont();
repositionAxes( ax );
repositionXLabel( ax );
end % onAxesFontChanged

%-------------------------------------------------------------------------%
function onAxesPositionChanged()
% We need to accept the new position, so remove the appdata before
% redrawing
if isappdata( ax, 'OriginalAxesPosition' )
rmappdata( ax, 'OriginalAxesPosition' );
end
if isappdata( ax, 'OriginalXLabelPosition' )
rmappdata( ax, 'OriginalXLabelPosition' );
end
repositionAxes( ax );
repositionXLabel( ax );
end % onAxesPositionChanged

%-------------------------------------------------------------------------%
function onAxesLimitsChanged()
% The limits have moved, so make sure the labels are still ok
textLabels = findall( ax, 'Tag', 'RotatedXTickLabel' );
xlim = get( ax, 'XLim' );
for tt=1:numel( textLabels )
xval = get( textLabels(tt), 'UserData' );
pos(1) = (xval-xlim(1)) / (xlim(2)-xlim(1));
pos(2) = 0;
% If the tick is off the edge, make it invisible
if xval<xlim(1) || xval>xlim(2)
set( textLabels(tt), 'Visible', 'off', 'Position', pos )
elseif ~strcmpi( get( textLabels(tt), 'Visible' ), 'on' )
set( textLabels(tt), 'Visible', 'on', 'Position', pos )
else
% Just set the position
set( textLabels(tt), 'Position', pos );
end
end

repositionXLabel( ax );

% xlab = get(ax,'XLabel');
% if ~strcmpi( get( xlab, 'Units' ), 'Data' )
% set( xlab, 'Units', 'data' );
% end
% pos = get( xlab, 'Position' );
% orig_yrange = diff( orig_ylim );
% new_yrange = diff( ylim );
% offset = (pos(2)-orig_ylim(1)) / orig_yrange;
% pos(2) = offset * new_yrange + ylim(1);
% pos(1) = mean( xlim );
% set( xlab, 'Position', pos );
% setappdata( ax, 'PreviousYLim', ylim );
end % onAxesPositionChanged

%-------------------------------------------------------------------------%
function addListeners( ax )
% Create listeners. We store the array of listeners in the axes to make
% sure that they have the same life-span as the axes they are listening to.
axh = handle( ax );
listeners = [
handle.listener( axh, findprop( axh, 'FontName' ), 'PropertyPostSet', @onAxesFontChanged )
handle.listener( axh, findprop( axh, 'FontSize' ), 'PropertyPostSet', @onAxesFontChanged )
handle.listener( axh, findprop( axh, 'FontWeight' ), 'PropertyPostSet', @onAxesFontChanged )
handle.listener( axh, findprop( axh, 'FontAngle' ), 'PropertyPostSet', @onAxesFontChanged )
handle.listener( axh, findprop( axh, 'FontUnits' ), 'PropertyPostSet', @onAxesFontChanged )
handle.listener( axh, findprop( axh, 'OuterPosition' ), 'PropertyPostSet', @onAxesPositionChanged )
handle.listener( axh, findprop( axh, 'XLim' ), 'PropertyPostSet', @onAxesLimitsChanged )
handle.listener( axh, findprop( axh, 'YLim' ), 'PropertyPostSet', @onAxesLimitsChanged )
];
setappdata( ax, 'RotateXLabelsListeners', listeners );
end % addListeners

%-------------------------------------------------------------------------%
function removeListeners( ax )
% Rempove any property listeners whilst we are fiddling with the axes
if isappdata( ax, 'RotateXLabelsListeners' )
delete( getappdata( ax, 'RotateXLabelsListeners' ) );
rmappdata( ax, 'RotateXLabelsListeners' );
end
end % removeListeners

end % EOF

draw_cm.m
function draw_cm(mat,tick,num_class)
%%
% Matlab code for visualization of confusion matrix;
% Parameters：mat: confusion matrix;
% tick: name of each class, e.g. 'class_1' 'class_2'...
% num_class: number of class
%
% Author： Page( 丕子)
% Blog: www.shamoxia.com;
% QQ:379115886;
% Email: peegeelee@gmail.com
%%
imagesc(1:num_class,1:num_class,mat); %# in color
colormap(flipud(gray)); %# for gray; black for large value.

textStrings = num2str(mat(:),'%0.2f');
textStrings = strtrim(cellstr(textStrings));
[x,y] = meshgrid(1:num_class);
hStrings = text(x(:),y(:),textStrings(:), 'HorizontalAlignment','center');
midValue = mean(get(gca,'CLim'));
textColors = repmat(mat(:) > midValue,1,3);
set(hStrings,{'Color'},num2cell(textColors,2)); %# Change the text colors

set(gca,'xticklabel',tick,'XAxisLocation','top');
set(gca, 'XTick', 1:num_class, 'YTick', 1:num_class);
set(gca,'yticklabel',tick);
rotateXLabels(gca, 315 );% rotate the x tick



compute_confusion_matrix.m
function [confusion_matrix]=compute_confusion_matrix(predict_label,num_in_class,name_class)%预测标签，每一类的数目，类别数目
%predict_label为一维行向量
%num_in_class代表每一类的个数
%name_class代表类名
num_class=length(num_in_class);
num_in_class=[0 num_in_class];
confusion_matrix=size(num_class,num_class);

for ci=1:num_class
for cj=1:num_class
summer=0;%统计对应标签个数
c_start=sum(num_in_class(1:ci))+1;
c_end=sum(num_in_class(1:ci+1));
summer=size(find(predict_label(c_start:c_end)==cj),2);
confusion_matrix(ci,cj)=summer/num_in_class(ci+1);
end
end

draw_cm(confusion_matrix,name_class,num_class);

end


测试代码：
testm.m

addpath('./ConfusionMatrices')
A=[1 2 1 1 2 2 3 2 3 3 3 3 4 4 1 4];
num=[4 4 4 4];
name=cell(1,4);
name{1}='haha';name{2}='hehe';name{3}='nani';name{4}='ok';
compute_confusion_matrix(A,num,name)



【附】直接用我借鉴的博客的代码得到的结果如下：