MATLAB: Increasing Decimal Point in Plot

axisdecimal pointplotresolution

I'm trying to plot a 10 million point data and the x-axis covers a range of 1 (i.e. 0 to 1). As I zoom in to view data, the x-axis label doesn't provide me with enough resolution. It's stuck at 4 decimal points while I need 7. I know one common solution is to set the gca xticklabel using a sprintf generated axis data. I've tried that but that only works when no zooming is involved. The axis values are stuck at the original no matter how much I zoom in.

So my question is how do I increase the decimal point of the axis label without resorting to using sprintf?

Would appreciate any help!

Best Answer

If you're using release R2015b or later, set the ruler's TickLabelFormat property, described in the Tick Values and Labels section of the numeric ruler properties documentation page.

In earlier releases, call zoom with an output and set that output's ActionPostCallback property to a function that updates the tick labels. See example 5 on the documentation page for zoom for an example you can adapt.

Related Solutions

MATLAB: How to prevent scientific notation on the axes in MATLAB R2015b and later

Starting in MATLAB R2015b, you can use axis ruler properties to customize the appearance of an individual axis. Please refer to the following examples for how you can remove scientific notation from your axis labels, in a way which is respected by zoom and pan.

In MATLAB R2016b and later:

>> h = plot(1:1000000, 1:1000000)
>> ax = ancestor(h, 'axes')
>> ax.XAxis.Exponent = 0
>> xtickformat('%.0f')

Setting the "Exponent" property of an axis to 0 removes the exponential notation common to all tick values. For more information, refer to the following documentation page:

https://www.mathworks.com/help/releases/R2019a/matlab/ref/matlab.graphics.axis.decorator.numericruler-properties.html#bun6izd-1-Exponent

The functions "xtickformat", "ytickformat", and "ztickformat" can then be used to customize the format of your tick labels. In this example, the format is set to fixed-point notation with zero decimal places, which removes the scientific notation from the individual tick labels. The following documentation page describes how to call the "xtickformat" function, and the additional formatting options which are available:

https://www.mathworks.com/help/matlab/ref/xtickformat.html

In MATLAB R2015b and R2016a:

>> h = plot(1:1000000, 1:1000000)
>> ax = ancestor(h, 'axes')
>> ax.XAxis.Exponent = 0
>> ax.XAxis.TickLabelFormat = '%.0f'

In releases R2015b and R2016a, you can use the "TickLabelFormat" property of an axis to customize the format of your labels. For more information on this property, refer to the following documentation page:

https://www.mathworks.com/help/releases/R2019a/matlab/ref/matlab.graphics.axis.decorator.numericruler-properties.html#bun6izd-1-TickLabelFormat

MATLAB: How to prevent scientific notation on the axes in MATLAB R2015a and earlier releases

If you are using MATLAB R2015b or a later release, please refer to the following MATLAB Answers post:

https://www.mathworks.com/matlabcentral/answers/466944-how-can-i-prevent-scientific-notation-on-my-axes-in-matlab-r2015b-and-later

In MATLAB R2015a and earlier releases, you can use the following method.

1. Plot your data.

>> x = rand(100, 1);
>> y = 1e-3*x;
>> plot(x, y)

2. Get a handle to the current figure and axes:

>> hFig = gcf
>> hAxes = gca

3. Define a function that reformats the tick labels as follows:

function reformatTickLabels(hAxes)
XTickLabel = get(hAxes,'XTick');
set(hAxes,'XTickLabel',num2str(XTickLabel'))
YTickLabel = get(hAxes,'YTick');
set(hAxes,'YTickLabel',num2str(YTickLabel'))
end

where "hAxes" is the axes handle.

4. Call this function to format your tick labels, before zooming.

>> reformatTickLabels(hAxes);

5. Get the handle to the zoom mode object of the figure:

>> z = zoom(hFig);

7. Set the "ActionPostCallback" function on the zoom handle to the function "reformatTickLabels". This means that after you perform a zooming action, this callback function will be called and executed. In this way, the tick labels will stay in non-scientific format even after zoom events.

set(z,'ActionPostCallback',@zoomReformatLabels)

where "zoomReformatLabels" is defined as

function zoomReformatLabels(obj,evd)
reformatTickLabels(evd.Axes)
end

where "obj" is the handle to the figure that has been clicked on and "evd" is the object containing the structure of event data.

More information on the zoom callback functions can be found here:

https://www.mathworks.com/help/releases/R2020a/matlab/ref/zoom.html

Note: This link is from MATLAB R2020a documentation. Some things might not be applicable for MATLAB R2015a as expected.

Best Answer

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MATLAB: How to prevent scientific notation on the axes in MATLAB R2015b and later

MATLAB: How to prevent scientific notation on the axes in MATLAB R2015a and earlier releases

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