Changing subplot data in MATLAB using slider function - matlab

Question

I have been trying to plot two images side by side with two sliders using uicontrol. I am relatively new to uicontrol using matlab. Only the second subplot updates when I change the slider.
close all;
clear all;
clc;
set(0,'defaultAxesFontSize',14)
set(0,'DefaultFigureWindowStyle','docked')
data = rand(3,1024,64,20);
nslice = size(data,4);
nidx = size(data,1);
if nslice == 1
sampling = 1; % in some of my data nslice would be 1 so I would like my slider to not give me error in such a case
else
sampling = 5;
end
idx = 1;
slice = 1;
h.f = figure(1);
x_axis = linspace(0,0.5,size(data,3));
y_axis = linspace(0,70,size(data,2));
set(h.f,'doublebuffer','on')
h.data = data;
inst_data = squeeze(data(nidx,:,:,slice));
h.ax(1) = subplot(1,2,1,'Parent',h.f,'Units','Normalized');
imagesc(h.ax(1),x_axis,y_axis, inst_data)
colorbar;
colormap(h.ax(1),'gray')
caxis(h.ax(1),[min(abs(inst_data(:))),max(abs(inst_data(:)))])
xlabel('xaxis')
ylabel('yaxis')
title('figure 1')
h.ax(2) = subplot(1,2,2,'Parent',h.f,'Units','Normalized');
log_data = log(inst_data);
imagesc(h.ax(2),x_axis,y_axis, log_data)
colorbar;
colormap(h.ax(2),'jet')
caxis(h.ax(2),[-max(abs(log_data(:))),max(abs(log_data(:)))])
xlabel('xaxis')
ylabel('yaxis')
title('figure 2')
sgtitle({'Sample data ', ['Slice: ',num2str(slice),' index: ', num2str(idx)]},'FontSize',16,'FontWeight','Bold')
h.slider1=uicontrol('Parent',h.f,...
'Units','Normalized',...
'Position',[0.1 0.06 0.8 0.05],...
'Style','slider',...
'SliderStep',[1,sampling],...
'Min',1,'Max',nslice,'Value',1,...
'Callback',{#slider_Callback,data,x_axis,y_axis});
txt1 = 'Slice';
txt2 = 'Index';
annotation('textbox', [0.05 0.07 0.05 0.04], 'string', txt1);
annotation('textbox', [0.05 0.021 0.05 0.04], 'string', txt2);
h.slider2=uicontrol('Parent',h.f,...
'Units','Normalized',...
'Position',[0.1 0.02 0.8 0.05],...
'Style','slider',...
'SliderStep',[1,1],...
'Min',1,'Max',nidx,'Value',1,...
'Callback',{#slider_Callback,data,x_axis,y_axis});
guidata(h.f,h)
%%
function slider_Callback(hObject,eventdata,data,x_axis,y_axis)%#ok<INUSD>
h=guidata(hObject);%retrieve struct
slice_i = round(get(h.slider1, 'Value'));
idx_i = round(get(h.slider2,'Value'));
inst = squeeze(data(idx_i,:,slice_i));
colorbar;
colormap(h.ax(1),'gray')
caxis(h.ax(1),[min(abs(inst(:))),max(abs(inst(:)))])
h.ax(1) = imagesc(x_axis,y_axis,inst); colorbar
lg = log(inst);
colorbar;
colormap(h.ax(2),'jet')
caxis(h.ax(2),[-max(abs(lg(:))),max(abs(lg(:)))])
h.ax(2) = imagesc(x_axis,y_axis, lg ); colorbar;
sgtitle({'Sample data ', ['Slice: ',num2str(slice_i),' index: ', num2str(idx_i)]},'FontSize',16,'FontWeight','Bold')
drawnow
end
Other problems include:
The slider slides with a floating value which shouldnt be the case
When my data has only 1 slice, the slider moves to value zero which shouldn't happen. You can try the same example with data = rand(3,1024,64,1);