Histogram: 'Greater than' bin

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Jessica Hiscocks
Jessica Hiscocks on 26 Apr 2018
Answered: Jessica Hiscocks on 26 Apr 2018
Simple question but I can't seem to find an answer: How do I add a bin to my histogram for the values outside of the visible range? Plotted automatically, the data below has values ranging from 0-200, the last 5 bins (100-200) have one point each. When I change the bin range to 0-100, those 5 bins are cut off. I want to take the points with values greater than the max(BinEdges) value, and have a bin labelled '>100' (populated dynamically as the bin edges are changed).
h=histogram(grains.area);
h.BinLimits=[0 100];
%Make range labels for bins
label = arrayfun(@(x,y) sprintf('%g - %g',x,y), ...
h.BinEdges(1:end-1), h.BinEdges(2:end), ...
'UniformOutput', false);
%label x axis with bin ranges
set(gca,'XTick',(h.BinEdges(1:end-1)+h.BinEdges(2:end))/2,...
'XTickLabel',label)
% get x position for bin count labels
xLblPos=h.BinEdges(1:end-1)+h.BinWidth/2;
%get y position
lift=max(h.Values)/20;
yLblPos=h.Values+lift;
%label each bar at top
cont=string(h.Values);
text(xLblPos,yLblPos,cont)

Accepted Answer

Steven Lord
Steven Lord on 26 Apr 2018
Add -Inf as the first element of the edges vector and/or Inf as the last element.
>> x = randn(1, 1e6);
>> h = histogram(x, [-Inf -2:0.25:2 Inf]);
>> tooSmallH = h.Values(1)
>> tooSmallX = nnz(x < -2)
>> tooLargeH = h.Values(end)
>> tooLargeX = nnz(x > 2)
The two variables whose names start with tooSmall should have the same value, as should the two variables whose names start with tooLarge.

More Answers (1)

Jessica Hiscocks
Jessica Hiscocks on 26 Apr 2018
The above mostly answered the question, but didn't label the x axis correctly. It did help me find the answer though:
%plot histogram, covering data from -inf to +inf
%use user set max and mins
userMin=0;
userMax=100;
width=round((userMax-userMin)/6,0);
h = histogram(grains.area, [-Inf userMin:width:userMax Inf]);
%adjust the x axis limits to fit the data
if min(grains.area)<userMin
a=userMin-width;
else
a=userMin;
end
if max(grains.area)>userMax
b=userMax+width;
else
b=userMax;
end
ax=gca;
ax.XLim=[a b];
%Make range labels for numeric bins
label = arrayfun(@(x,y) sprintf('%g - %g',x,y), ...
h.BinEdges(1:end-1), h.BinEdges(2:end), ...
'UniformOutput', false);
%add label for 'over' bin
%label x axis with bin ranges
set(gca,'XTick',(h.BinEdges(1:end-1)+h.BinEdges(2:end))/2,...
'XTickLabel',label)
%manually adjust the xtics to have the even spacing (or else -inf and +inf
%plotted far off scale)
ax.XTick(1)=h.BinEdges(1)-width/2;
ax.XTick(end)=h.BinEdges(end-1)+width/2;
% get x position for bin count labels
xLblPos=ax.XTick;
%get y position
lift=max(h.Values)/20;
yLblPos=h.Values+lift;
%label each bar at top
cont=string(h.Values);
text(xLblPos,yLblPos,cont)

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