Try something like this
value = str2double(handles.edittext1.String)
if handles.popupmenu1.Value == 1
if handles.popupmenu2.Value == 1
convertedValue = value * 123.4567; % Or whatever it is.
elseif handles.popupmenu2.Value == 2
elseif handles.popupmenu2.Value == 3
elseif handles.popupmenu2.Value == 4
elseif handles.popupmenu2.Value == 5
end
elseif handles.popupmenu1.Value == 2
if handles.popupmenu2.Value == 1
elseif handles.popupmenu2.Value == 2
elseif handles.popupmenu2.Value == 3
elseif handles.popupmenu2.Value == 4
elseif handles.popupmenu2.Value == 5
end
elseif handles.popupmenu1.Value == 3
if handles.popupmenu2.Value == 1
elseif handles.popupmenu2.Value == 2
elseif handles.popupmenu2.Value == 3
elseif handles.popupmenu2.Value == 4
elseif handles.popupmenu2.Value == 5
end
elseif handles.popupmenu1.Value == 3
if handles.popupmenu2.Value == 1
elseif handles.popupmenu2.Value == 2
elseif handles.popupmenu2.Value == 3
elseif handles.popupmenu2.Value == 4
elseif handles.popupmenu2.Value == 5
end
elseif handles.popupmenu1.Value == 5
if handles.popupmenu2.Value == 1
elseif handles.popupmenu2.Value == 2
elseif handles.popupmenu2.Value == 3
elseif handles.popupmenu2.Value == 4
elseif handles.popupmenu2.Value == 5
end
end
handles.edittext2.String = sprintf('In those units, the value is %f', convertedValue)
Inside each if block, do the conversion, or get the scaling factor, for the relevant pair that was chosen.
