# Plotting time series in years BP? **URL:** \ **Category:** Q&A\ **Created:** [June 8, 2022, 2:51pm UTC](https://forum.generic-mapping-tools.org/t/plotting-time-series-in-years-bp/3007 "2022-06-08T14:51:03Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![paul](https://avatars.discourse-cdn.com/v4/letter/p/bbe5ce/32.png) [@paul](https://forum.generic-mapping-tools.org/u/paul)\ **Post date:** [June 8, 2022, 2:51pm UTC](https://forum.generic-mapping-tools.org/t/plotting-time-series-in-years-bp/3007/1 "2022-06-08T14:51:03Z")
Dear Forum, I am a newbee here but have been using GMT on macs ever since the Tennon Unix emulator days, but the one thing I have never done till now was to plot a time series in years BP where the left x-axis value is larger than the right x-axis value, e.g., -R5500/3500/0/1 (which of course programs like psxy will not like). Could there be someone out there who can direct me to a solution? Thanks! -pjk ---
**Author:** ![Jose-Alvarez](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/jose-alvarez/32/76_2.png) [@Jose-Alvarez](https://forum.generic-mapping-tools.org/u/Jose-Alvarez)\ **Post date:** [June 8, 2022, 3:17pm UTC](https://forum.generic-mapping-tools.org/t/plotting-time-series-in-years-bp/3007/2 "2022-06-08T15:17:00Z")
Hi Paul, You just need to tell GMT to plot the axis inverted in the projection using negative values. for example you can do: basemap -R3500/5500/0/1 -JX-12c/4c -Ba to obtain the desired result. Note the -12c as scale for the x axis. Regards Jose ---
**Author:** ![paul](https://avatars.discourse-cdn.com/v4/letter/p/bbe5ce/32.png) [@paul](https://forum.generic-mapping-tools.org/u/paul)\ **Post date:** [June 8, 2022, 4:12pm UTC](https://forum.generic-mapping-tools.org/t/plotting-time-series-in-years-bp/3007/3 "2022-06-08T16:12:59Z")
Super Big Thanks Jose! That worked! I never thought to look for an option on -J, only -R. Now your example makes sense.