Possible vs. Used Observations

This example demonstrates how to read and observation sequence file, and view the number of used versus possible observations by type.

Import the obs_sequence module

import pydartdiags.obs_sequence.obs_sequence as obsq

Chose an obs_seq file to read. This is a small obs_seq file “obs_seq.final.ascii.small” that comes with the pyDARTdiags package in the data directory, so we import os to get the path to the file

import os
data_dir = os.path.join(os.getcwd(), "../..", "data")
data_file = os.path.join(data_dir, "obs_seq.final.ascii.small")

read the obs_seq file into an obs_seq object

obs_seq = obsq.ObsSequence(data_file)

Examine the dataframe

obs_seq.df.head()

	obs_num	observation	prior_ensemble_mean	prior_ensemble_spread	prior_ensemble_member_1	prior_ensemble_member_2	prior_ensemble_member_3	prior_ensemble_member_4	prior_ensemble_member_5	prior_ensemble_member_6	prior_ensemble_member_7	prior_ensemble_member_8	prior_ensemble_member_9	prior_ensemble_member_10	prior_ensemble_member_11	prior_ensemble_member_12	prior_ensemble_member_13	prior_ensemble_member_14	prior_ensemble_member_15	prior_ensemble_member_16	prior_ensemble_member_17	prior_ensemble_member_18	prior_ensemble_member_19	prior_ensemble_member_20	prior_ensemble_member_21	prior_ensemble_member_22	prior_ensemble_member_23	prior_ensemble_member_24	prior_ensemble_member_25	prior_ensemble_member_26	prior_ensemble_member_27	prior_ensemble_member_28	prior_ensemble_member_29	prior_ensemble_member_30	prior_ensemble_member_31	prior_ensemble_member_32	prior_ensemble_member_33	prior_ensemble_member_34	prior_ensemble_member_35	prior_ensemble_member_36	...	prior_ensemble_member_55	prior_ensemble_member_56	prior_ensemble_member_57	prior_ensemble_member_58	prior_ensemble_member_59	prior_ensemble_member_60	prior_ensemble_member_61	prior_ensemble_member_62	prior_ensemble_member_63	prior_ensemble_member_64	prior_ensemble_member_65	prior_ensemble_member_66	prior_ensemble_member_67	prior_ensemble_member_68	prior_ensemble_member_69	prior_ensemble_member_70	prior_ensemble_member_71	prior_ensemble_member_72	prior_ensemble_member_73	prior_ensemble_member_74	prior_ensemble_member_75	prior_ensemble_member_76	prior_ensemble_member_77	prior_ensemble_member_78	prior_ensemble_member_79	prior_ensemble_member_80	Data_QC	DART_quality_control	linked_list	longitude	latitude	vertical	vert_unit	type	metadata	external_FO	seconds	days	time	obs_err_var
0	1	230.16	231.310652	0.405191	231.304725	231.562874	231.333915	231.297690	232.081416	231.051063	230.972638	231.027194	232.130965	231.360344	231.053641	231.435224	231.699212	231.377938	230.941798	230.582642	231.110502	231.896842	231.186579	230.509482	231.048492	231.204990	231.591243	231.365841	231.399177	231.255679	231.481019	231.409253	231.514708	231.446422	230.389279	231.337093	231.101248	231.303085	230.959715	230.910665	...	231.264020	231.250437	231.464351	230.930660	231.857375	231.622277	231.782818	230.955721	231.990693	230.706116	231.349281	231.494425	230.700074	231.609108	230.548519	231.321679	231.396247	231.850075	231.632897	231.521874	231.518307	231.433581	231.507273	230.523739	231.631744	231.405045	1.0	0.0	-1 2 -1	274.460	40.010	23950.0	pressure (Pa)	ACARS_TEMPERATURE	[]	[]	75603	153005	2019-12-01 21:00:03	1.00
1	2	18.40	15.720527	0.630827	14.217207	15.558196	15.805599	16.594644	14.877743	16.334438	16.194266	16.019533	15.277846	15.373408	14.594145	16.803848	15.444847	15.704984	15.629746	16.565236	15.107416	15.546187	15.123756	15.073689	15.531795	16.281052	16.160298	14.627017	15.297628	15.845782	15.321642	16.374810	15.886537	15.699854	15.734169	15.728008	15.241341	15.990183	16.049381	15.238145	...	16.789844	16.188690	15.061255	14.611386	14.714651	15.942698	14.992799	15.177780	15.364643	15.136918	15.143889	16.209363	17.056931	15.556262	15.026830	15.847185	15.604588	16.421213	16.124153	16.685584	15.734904	15.757099	15.477638	15.207487	15.698581	15.587689	1.0	0.0	1 3 -1	274.460	40.010	23950.0	pressure (Pa)	ACARS_U_WIND_COMPONENT	[]	[]	75603	153005	2019-12-01 21:00:03	6.25
2	3	1.60	-4.932073	0.825899	-5.270562	-5.955998	-4.209766	-5.105016	-4.669405	-4.365305	-4.488440	-4.359430	-4.784306	-4.726351	-3.267393	-4.463462	-2.894223	-5.692221	-4.134282	-6.064812	-6.414516	-6.440465	-5.200572	-5.236082	-5.369967	-7.115516	-4.953035	-5.120461	-4.721911	-5.939821	-6.075857	-4.667864	-6.316152	-4.438065	-5.852839	-4.417175	-4.404990	-4.570971	-3.735192	-5.350288	...	-5.917664	-5.111100	-6.057586	-3.555137	-4.674986	-5.335997	-4.621651	-5.584179	-5.195837	-3.465590	-4.522163	-5.468159	-5.969632	-4.170915	-6.012171	-5.040896	-5.049011	-4.545161	-5.091350	-4.861851	-4.874598	-3.727132	-5.355879	-3.996374	-5.190794	-5.027215	1.0	0.0	2 4 -1	274.460	40.010	23950.0	pressure (Pa)	ACARS_V_WIND_COMPONENT	[]	[]	75603	153005	2019-12-01 21:00:03	6.25
3	4	264.16	264.060532	0.035584	264.107192	264.097270	264.073212	264.047718	264.074140	264.019895	264.128792	264.007258	264.090781	264.066146	264.072458	264.016448	264.047761	264.047443	264.079061	264.019732	264.068371	264.045445	264.007536	264.053554	264.046485	264.030441	264.086369	264.124872	264.055288	264.015123	264.024744	264.038656	264.063976	264.020976	264.114508	264.105652	264.088124	264.045258	264.056010	264.029595	...	264.063943	264.063542	264.057365	264.052744	264.081657	264.021780	264.053569	264.040506	264.099816	264.084574	264.099814	263.996423	264.108304	264.031686	264.057295	264.093241	264.085667	264.123769	264.064173	264.035075	264.062793	264.020287	264.041890	263.997670	264.093310	263.995671	1.0	0.0	3 5 -1	242.628	34.105	56260.0	pressure (Pa)	ACARS_TEMPERATURE	[]	[]	75603	153005	2019-12-01 21:00:03	1.00
4	5	11.60	10.134115	0.063183	10.067956	10.078798	10.120263	10.084885	10.135112	10.140610	10.123242	10.186508	10.148250	10.202592	10.080998	10.225761	10.202466	10.149097	10.144331	10.227488	10.097538	10.177305	10.227193	10.175335	10.127163	10.189796	10.105735	10.006187	10.157041	10.197396	10.202818	10.163028	10.184205	10.246155	10.089909	10.052000	10.065482	10.136479	10.019034	10.229759	...	10.091969	10.114748	10.090966	10.118479	10.183483	10.133319	10.131281	10.133985	10.065029	10.077334	10.128657	10.285550	10.113482	10.217276	10.059962	10.074082	10.183239	9.944888	10.168632	10.155279	10.143549	10.189449	10.103469	10.189495	10.056878	10.147228	1.0	0.0	4 6 -1	242.628	34.105	56260.0	pressure (Pa)	ACARS_U_WIND_COMPONENT	[]	[]	75603	153005	2019-12-01 21:00:03	6.25

5 rows × 98 columns

Find number of used versus possible observations

obs_seq.possible_vs_used()

	type	possible	used
0	ACARS_TEMPERATURE	3	2
1	ACARS_U_WIND_COMPONENT	2	2
2	ACARS_V_WIND_COMPONENT	2	2
3	AIRCRAFT_TEMPERATURE	1	1
4	AIRCRAFT_U_WIND_COMPONENT	1	1
5	AIRCRAFT_V_WIND_COMPONENT	1	1