Plotting image and data changes y-axis direction. Why and how to fi... (2025)

Does the command

axis ij % makes the y axis point downward

placed after the plot command, help?

Hi Dhairya Mehta,

It is my understanding that the while plotting the cordinates on image the cordinates are being changed.

I assume you you gave the coordinates wrong,Refer to these ,

From the "More About" section on the documentation page for the image function:

"The image function has two versions, the high-level version and the low-level version. If you use image with 'CData' as an input argument, then you are using the low-level version. Otherwise, you are using the high-level version.

The high-level version of image calls newplot before plotting and sets these axes properties:

• Layer to 'top'. The image is shown in front of any tick marks or grid lines.
• YDir to 'reverse'. Values along the y-axis increase from top to bottom. To decrease the values from top to bottom, set YDir to 'normal'. This setting reverses both the y-axis and the image.
• View to [0 90].

The low-level version of the image function does not call newplot and does not set these axes properties."

The relevant piece of this information for your application is the second bullet that discusses the axes YDir property. You can:

• change this property of the axes manually after you've called image (if you change it before, image will change it as part of its execution), or
• you could call the low-level version of the image function, or
• you could use the axis function with 'xy' as input. See the axis function documentation for more information on the 'xy' option