# How to fix 'pygmt-session \[ERROR\]: Not available in classic mode' **URL:** \ **Category:** PyGMT Q&A\ **Created:** [January 8, 2024, 2:13pm UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573 "2024-01-08T14:13:48Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 8, 2024, 2:13pm UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/1 "2024-01-08T14:13:48Z")
Hello everyone! I encountered some difficulties while using PyGMT. When I use ‘fig = gmt.Figure()’ in a function, an error is returned: ‘pygmt-session [ERROR]: Not available in classic mode’ I tried solution given by:[https://github.com/GenericMappingTools/pygmt/issues/217](https://github.com/GenericMappingTools/pygmt/issues/217) After I added ‘reload(pygmt)’, a new error comes out: ‘free(): invalid next size (fast)’ or 'double free or corruption (out) How to fix this problem? I hope some of you could help me. Thanks in advance 😀 ---
**Author:** ![weiji14](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/weiji14/32/33_2.png) [@weiji14](https://forum.generic-mapping-tools.org/u/weiji14)\ **Post date:** [January 8, 2024, 10:00pm UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/2 "2024-01-08T22:00:11Z")
Hi @sherfy, thanks for reporting the issue. Could you provide the output of: ```auto import pygmt pygmt.show_versions() ``` Just want to see what version of GMT/PyGMT you have installed. > [@sherfy](#): > > ‘free(): invalid next size (fast)’ or 'double free or corruption (out) Is this error happening on `reload(pygmt)`, or another line in your Python script? If it is another function (e.g. `fig.plot()`), could you turn on debugging mode using e.g. `fig.plot(..., verbose=True)`, and post the output from that? That would make it easier to know where the issue is. ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 4:26am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/3 "2024-01-09T04:26:30Z")
Thank you for responding to my question. The version of my PyGMT is: 6.4.0. And my full error is: > pygmt-session [ERROR]: Not available in classic mode > Module ‘figure’ failed with status code 30 I tried to add ‘verbose=True’, and here is my output: > plot [INFORMATION]: Processing input table data > plot [INFORMATION]: Central meridian not given, default to 127.95 > plot [INFORMATION]: Map scale is 7.79236 km per cm or 1:779236. > plot [INFORMATION]: Reading Data Table from Input memory location via vector > double free or corruption (out) > Aborted (core dumped) ---
**Author:** ![seisman](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/seisman/32/4_2.png) [@seisman](https://forum.generic-mapping-tools.org/u/seisman)\ **Post date:** [January 9, 2024, 7:37am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/4 "2024-01-09T07:37:45Z")
Open a terminal, run the command `gmt clear sessions`, and then try your Python script again. ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 7:47am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/5 "2024-01-09T07:47:05Z")
I tried it and it only worked once and then I got the same error again. ---
**Author:** ![seisman](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/seisman/32/4_2.png) [@seisman](https://forum.generic-mapping-tools.org/u/seisman)\ **Post date:** [January 9, 2024, 8:00am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/6 "2024-01-09T08:00:09Z")
OK, now I know the reason. Since your Python script crashes, the GMT session is not correctly ended. Could you please try run `gmt clear sessions` again, and then run the following commands in your Python interpreter: ```auto import pygmt pygmt.show_versions() ``` ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 8:05am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/7 "2024-01-09T08:05:46Z")
ok, the output is: > version: 6.4.0 I just tried: > sudo apt install libtcmalloc-minimal4 > export LD\_PRELOAD=“/usr/lib/x86\_64-linux-gnu/libtcmalloc\_minimal.so.4” After I used this method, the problem was solved. But I still don’t understand why this problem occurs. ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 9:18am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/8 "2024-01-09T09:18:10Z")
> [@seisman](#): > > ```auto > import pygmt > > pygmt.show_versions() > > ``` Sorry, here is my full output: > > > > pygmt.show\_versions() > > > > PyGMT information: > > > > version: v0.10.0 > > > > System information: > > > > python: 3.11.0 | packaged by conda-forge | (main, Jan 14 2023, 12:27:40) [GCC 11.3.0] > > > > executable: /home/user/anaconda3/envs/SWS/bin/python > > > > machine: Linux-5.15.0-82-generic-x86\_64-with-glibc2.31 > > > > Dependency information: > > > > numpy: 1.26.2 > > > > pandas: 2.1.4 > > > > xarray: 2023.6.0 > > > > netCDF4: 1.6.2 > > > > packaging: 23.1 > > > > contextily: None > > > > geopandas: None > > > > IPython: 8.19.0 > > > > rioxarray: None > > > > ghostscript: 10.02.1 > > > > GMT library information: > > > > binary version: 6.4.0 > > > > cores: 192 > > > > grid layout: rows > > > > image layout: > > > > library path: /home/user/anaconda3/envs/SWS/lib/libgmt.so > > > > padding: 2 > > > > plugin dir: /home/user/anaconda3/envs/SWS/lib/gmt/plugins > > > > share dir: /home/user/anaconda3/envs/SWS/share/gmt > > > > version: 6.4.0 ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 9:19am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/9 "2024-01-09T09:19:43Z")
I use this method solved the problem:double free or corruption (out). But a new one has arisen, I will have Segmentation fault (core dumped) when I run my code. ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 9:20am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/10 "2024-01-09T09:20:23Z")
> [@sherfy](#): > > sudo apt install libtcmalloc-minimal4 > export LD\_PRELOAD=“/usr/lib/x86\_64-linux-gnu/libtcmalloc\_minimal.so.4” I use this method solved the problem:double free or corruption (out). But a new one has arisen, I will have Segmentation fault (core dumped) when I run my code. ---
**Author:** ![seisman](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/seisman/32/4_2.png) [@seisman](https://forum.generic-mapping-tools.org/u/seisman)\ **Post date:** [January 9, 2024, 10:27am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/11 "2024-01-09T10:27:22Z")
Can you share the Python script you’re running? ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 10:40am UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/12 "2024-01-09T10:40:06Z")
> [@seisman](#): > > Python script Sure. ``` def plot_2d_map(region,lon,lat,station_lat,station_long,depth,grd_path,data_path): mindepth = float(min(depth))/1000 fig = pygmt.Figure() pygmt.config(MAP_FRAME_TYPE="plain", FONT_ANNOT_PRIMARY="14p") fig.basemap(region=region, projection="M10c",frame="a") fig.coast( projection="M10c", region=region, frame="a", land="white", water="lightblue", borders="1/1p,black", ) pygmt.makecpt( cmap="gray", series="0.95/1/0.01", continuous=True ) fig.grdimage( grid=os.path.join(grd_path,'earth_relief_15s.grd'), region=region, projection="M10c", shading="+a-20+nt0.5+m0", cmap=True, frame=True ) fig.plot(x=lon,y=lat,style="c0.15c",fill='black') fig.plot(x=station_long,y=station_lat,style="t0.3c",fill='black') fig.savefig(os.path.join(data_path,'map.png')) return 1 def plot_3d(region1,region2,lon,lat,depth,timelist,grd_path,data_path): # PyGMT Figure fig = pygmt.Figure() # Set the azimuth and elevation angle perspective = [220, 30] # Plot 3D scatter points fig.plot3d( region=region2, x=lon, y=lat, z=depth, projection="M5c", style="g0.2c", pen="black", fill='black', frame=[ "WSZ4", 'xag+l"latitude"', 'yag+l"longitude"', "z+ldepth(m)", ], perspective=perspective, ) # Plot basemap fig.shift_origin(yshift=8) fig.coast(region=region1, projection='M5c', shorelines='0.25p,black', land='grey90', perspective=perspective,) pygmt.makecpt( cmap="gray", series="0.95/1/0.01", continuous=True ) fig.grdimage( grid=os.path.join(grd_path,'earth_relief_15s.grd'), region=region1, projection="M5c", shading="+a-20+nt0.5+m0", cmap=True, frame=True, perspective=perspective ) fig.savefig(os.path.join(data_path,'3d.png')) return def plot_map(data_path,station_path,grd_path): station_list = np.loadtxt(station_path,dtype=str) station_long = station_list[:,4] station_lat = station_list[:,3] data = np.loadtxt(os.path.join(data_path,'location.txt'),dtype='str',delimiter=' ') time = data[:,0] lon = [float(x) for x in data[:,2]] lat = [float(x) for x in data[:,3]] depth = [float(x) for x in data[:,4]] timelist = pd.DataFrame({ 'time': time, 'value': np.random.rand(len(time)) }) timelist['time'] = timelist['time'].astype("datetime64[ns]") minlon, maxlon = round(float(min(station_long))-0.1,1),round(float(max(station_long))+0.1,1) minlat, maxlat = round(float(min(station_lat))-0.1,1),round(float(max(station_lat))+0.1,1) maxdepth = float(max(depth))/1000 region1 = [minlon, maxlon, minlat, maxlat] region2 = [minlon, maxlon, minlat, maxlat,-maxdepth, 0] plot_2d_map(region1,lon,lat,station_lat,station_long,depth,grd_path,data_path) plot_3d(region1,region2,lon,lat,depth,timelist,grd_path,data_path) if __name__ == ' __main__': data_path = config.get_Location_save_path() station_path = config.get_station_file() grd_path = config.get_ppt_file_path() plot_map(data_path,station_path,grd_path) ``` ---
**Author:** ![sherfy](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@sherfy](https://forum.generic-mapping-tools.org/u/sherfy)\ **Post date:** [January 9, 2024, 4:00pm UTC](https://forum.generic-mapping-tools.org/t/how-to-fix-pygmt-session-error-not-available-in-classic-mode/4573/13 "2024-01-09T16:00:39Z")
Thank you for your answers. I really appreciate you helping me with this. 😃 The problem should be caused by the bash GMT code with os.system before running this code. 😂 But how to close the GMT correctly? By using the “gmt clear sessions”?