Continuous data plot through arduino on a Matlab GUI

A code for plotting sesnor values from arduino on matlab gui -

w = 0;

x = 0;

y = 0;

z = 0;

o=0;

go = true;

global a;

while go

value1 = readVoltage(a,'A1');

value2 = readVoltage(a,'A2');

value3 = readVoltage(a,'A3');

value4 = readVoltage(a,'A4');

w = [w value1];

x = [x value2];

y = [y value3];

z = [z value4];

plot(handles.axes1,w);

plot(handles.axes2,x);

plot(handles.axes3,y);

plot(handles.axes4,z);

drawnow;

end

the above code plots the following data -

what is the x axis and y axis range? is the y axis as mV and x axis as micro or miliseconds?