PHP: line charts

Answer 1

The second pic seems to be drawn pixel by pixel with setpixel function (in case of GD extension). All you need is to fill the lower pixels with a color after drawing the one representing value.

If you would like to make a similar graph as on pic1 but filled with a color you can use imagefilledpolygon function to draw the graph.

Answer 2

We generally use a commercial component for graphs. It uses flash but as great functionnalities and customization capabilities.

If you want some jpeg or gif picture graphs, in the far past we used to work with jpgraph which is now PHP5 and Object oriented.

Answer 3

I'm not sure what you're using, but the excellent pChart library can do this: