How to resize image with ImageMagick with a max width/height

Resize image with max width and height

set max width:600 max height 400

convert image.jpg -resize 600x400\> image.jpg

Resize image with max width and keep aspect ratio

set max width 1024

convert image.jpg -resize 1024\> image.jpg

Resize image with max height and keep aspect ratio

set max height 800

convert image.jpg -resize x800\> image.jpg