# How to get position coordinates of axes' ticks?

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Dominik Mattioli on 19 Jul 2021
Commented: dpb on 20 Jul 2021
I would like to know the intersection points of the X and Y major grid lines for an axis, with respect to the parent figure. I have some code that does this, but I'm wondering if there is a getter call for the axis object, given that the 'grid on' and 'grid minor' calls plot lines that intersect with the desired points:
% Init fig and axis.
f = figure( 'Color', 'w', 'WindowState', 'Maximized', 'Units', 'Points' );
ax = axes( 'Parent', f, 'Layer', 'Bottom', 'Units', 'Points',...
'XTick', 0:.1:1, 'XTickLabels', strsplit( num2str( 0:.1:1 ) ),...
'YTick', 0:.1:1, 'YTickLabels', strsplit( num2str( 0:.1:1 ) ) );
axP = ax.get( 'Position' );
% Get coordinates of each grid line.
xRuler = ax.get( 'XAxis' );
xRulerTickIndices = xRuler.get( 'TickValues' );
xRulerTickPos = linspace( axP( 1 ), axP( 1 ) + axP( 3 ), numel( xRulerTickIndices ) );
yRuler = ax.get( 'YAxis' );
yRulerTickIndices = yRuler.get( 'TickValues' );
yRulerTickPos = linspace( axP( 2 ), axP( 2 ) + axP( 4 ), numel( yRulerTickIndices ) );
[XGrid, YGrid] = meshgrid( xRulerTickPos, yRulerTickPos );
widths = diff( xRulerTickPos( 1:2 ) ) / 4;
heights = diff( yRulerTickPos( 1:2 ) ) / 4;
% Plot axes at each point.
newAx = gobjects( size( XGrid ) );
for idx = 1:size( XGrid, 1 )
for jdx = 1:size( XGrid, 2 )
newAxPos = horzcat( XGrid( idx, jdx ) - widths/2, YGrid( idx, jdx ) - heights/2, widths, heights );
newAx( idx, jdx ) = axes( 'Parent', f, 'Layer', 'Top', 'Units', 'Points', 'Position', newAxPos );
end
end
Edit: this code assumes tick marks that are equidistant from each other and from the box limits, so this code is not generalizable.
Edit2: The axes that I would plot at these points would vary in size while still aligning with the ticks of the main axis. I don't think subplot() or tiledlayout() will be useful for my purpose.
dpb on 20 Jul 2021
I'd note the above code could be written much more compactly --
% Init fig and axis.
hF= figure( 'Color', 'w', 'WindowState', 'Maximized', 'Units', 'Points' );
hAx=axes(hF, 'Layer','Bottom', 'Units','Points'); % default ticks, tick labels match 0:0.1:1
axP = hAx.Position; % dot notation more concise
% Get coordinates of each grid line.
xRuler = hAx.XAxis;
xRulerTickIndices=xticks;
...