[R] multi-regression with more than 50 independent variables

[R DF]

Hi R Users,

I am going to run a multiple linear regression with around 57 independent
variables. Each time I run the model with just 11 variables, the results
are reasonable. With increasing the number of independent variables more
than 11, the coefficients will get “NA” in the output.  Is there any
limitation for the number of independent variables in multiple linear
regressions in R? I attached my dataset as well as R codes below:



mlr.data<- read.table("./multiple.txt",header=T)

mlr.output<- lm(formula = CaV ~ SHG +  TrD+  CrH+ SPAD+ FlN+ FrN+   YT+
LA+ LDMP+    B+Cu+  Zn+   Mn +   Fe+   K +  P+   N +Clay30 +Silt30 +Sand30
+Clay60 +Silt60 +Sand60 +ESP30 +NaEx30+ CEC30+Cl30+ SAR30 +KSol30+ NaSol30
+CaMgSol3 +ZnAv30 +FeAv30 +OC30 +PAv30 +KAv30 +TNV30+ pH30+ EC30 +SP30
+ESP60 +NaEx60 +CEC60  +Cl60 +SAR60 +KSol60 +NaSol60 +CaMgSol6
+ZnAv60+FeAv60 +OC60 +PAv60 +KAv60 +TNV60 +pH60 + EC60 +SP60, data=mlr.data)

summary (mlr.output)




Regards,

Reza
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CaV	SHG	TrD	CrH	SPAD	FlN	FrN	YT	LA	LDMP	B	Cu	Zn	Mn	Fe	K	P	N	Clay30	Silt30	Sand30	Clay60	Silt60	Sand60	ESP30	NaEx30	CEC30	Cl30	SAR30	KSol30	NaSol30	CaMgSol3	ZnAv30	FeAv30	OC30	PAv30	KAv30	TNV30	pH30	EC30	SP30	ESP60	NaEx60	CEC60	Cl60	SAR60	KSol60	NaSol60	CaMgSol6	ZnAv60	FeAv60	OC60	PAv60	KAv60	TNV60	pH60	EC60	SP60
49.83	15.8	22.32	45.8	82.7	126	5	55.8	34.7	57.7	17.9	8.4	14.7	50.5	144.7	0.9	0.1	1.7	14	50	36	10	26	64	3.2	0.3	11.9	87.7	5.6	2.5	25.7	69.8	2.9	3.1	0.66	64.4	360	14.8	9.94	0.6	39.6	4.8	0.2	12.2	51.4	6.9	1.4	33.4	69.9	1.8	3.4	0.2	3.5	290	11.5	7.19	3.21	40.1
37.85	18.9	20.89	53.2	75.9	169	4	67.4	40.1	58.6	15.8	7.9	12.1	53.2	141.6	0.7	0.1	1.9	13	51	34	11	28	64.0	1.9	0.2	12.5	45.7	7.8	3.8	22.9	77.9	3.1	2.5	0.69	45.6	390	14.8	7.2	1.1	40.1	5.4	0.1	13.3	59.9	7.9	1.7	56.6	58.9	1.5	5.5	0.6	1.9	350	10.2	7.1	3.7	42.1
64.12	20.7	19.04	43.9	74.3	133	5	55.9	38.7	60.0	12.1	6.3	12.6	47.4	159.5	1.0	0.1	1.6	12	48	33	13	26	62.0	6.4	1.1	12.6	33.2	10.1	1.8	43.8	99.3	1.5	2.8	0.57	20.5	470	15.1	7.1	0.7	39.8	4.9	0.3	10.9	65.5	7.1	2.3	42.1	66.4	1.1	3.9	0.7	2.9	288.9	12.2	7.2	4.1	35.6
90.28	14.6	19.52	56.9	61.9	145	7	66.5	33.2	59.1	13.7	4.7	10.0	52.1	241.1	0.8	0.1	1.9	13	47	32	10	30	57.0	5.5	0.3	11.7	31.2	3.5	2.4	50.4	65.7	1.9	2.5	0.88	41.9	398	14.3	7	2.4	38.7	3.1	0.5	14.1	71.9	8.4	1.9	36.7	59.1	0.9	2.6	0.5	2.7	290.7	13.6	7	2.6	43.7
111.18	13.2	16.53	61.3	78	127	6	49.9	41.7	51.6	14.7	4.7	10.0	55.8	148.9	0.7	0.1	1.9	14	46	37	11	28	60.0	3.9	0.7	11	21.7	4.3	0.9	33.7	73.6	2.3	2.7	0.78	33.4	349	15.2	7.4	0.9	39.1	2.8	0.1	12.5	76.6	8.9	3.1	32.1	71.4	0.5	6.9	0.5	2.5	256.9	15.1	7.5	1.7	36.7
59.11	12.9	21.34	45.3	78.9	178	6	63.3	39.8	52.0	19.5	4.2	8.9	54.7	229.5	0.7	0.1	1.7	13	46	36	12	30	62.0	2.7	0.7	12.9	19.5	2.6	2.8	61.2	86.9	2.2	3.7	0.86	27.8	400.5	17.1	7.1	2.1	39.9	3.9	0.3	11.9	57.4	6.7	1.6	30.1	89.9	1.8	5.8	0.3	3.7	224.8	12.9	7.3	5.5	34.9
80.89	17.9	15.86	40.3	66.8	154	7	45.6	36.8	47.8	21.6	3.7	12.6	54.7	162.1	0.7	0.1	1.9	11	50	35	13	31	61.0	2.9	0.4	10.9	37.9	7.1	1.9	19.5	55.8	2.8	2.9	0.66	45.1	459	15.6	7.2	0.8	36.1	5.1	0.4	13.1	85.5	5.7	2.1	29.1	92.1	1.9	7.8	0.7	2.8	278.9	11.8	7.2	6.1	32.7
122.74	16.6	17.29	43	77.8	140	6	32.9	37.7	55.6	20.0	4.2	12.1	47.4	152.6	0.9	0.1	1.7	14	49	36	11	25	58.0	3.2	1.5	11.5	24.5	3.9	3.7	20.8	56.9	1.9	2.6	0.72	40.7	398	16.3	7.3	0.7	37.7	2.2	0.1	11.8	55.5	6.1	1.8	39.9	69.9	2.1	2.4	0.3	1.8	312.8	10.6	7.4	7.3	31.2
20.08	7.6	18.28	33.8	60.5	81	1	11.3	37.0	59.8	21.3	3.2	4.9	67.5	153.4	0.5	0.1	0.7	16	46	38	15	45	40	7.7	0.8	11.2	139.8	10.7	1.3	80.7	106.6	2.4	2.4	0.6	10.9	345.8	14.8	7.5	12.2	36.3	6.3	0.7	10.5	108.2	9.8	0.5	63.7	84.4	1.3	2.5	0.4	3.3	213.0	15.7	7.6	10.5	38.2
22.09	11.8	14.44	40.3	61.4	67	2	13.5	34.6	58.7	21.6	2.6	7.6	57.4	186.5	0.5	0.1	0.6	13	48	35	12	30	59	6.8	0.8	12.1	45.8	5.6	1.0	26.1	37.1	1.3	2.5	0.6	4.3	407.2	17.5	7.7	4.7	34.5	6.9	0.8	12.0	65.9	7.4	0.7	38.2	50.9	0.9	2.9	0.4	1.9	265.3	18.3	7.6	6.8	35.2
25.04	8.4	15.29	46.3	65.5	60	1	11.0	33.2	56.2	21.4	2.2	10.1	54.6	167.8	0.4	0.1	0.8	13	48	35	12	30	58	11.3	1.2	10.4	79.7	10.4	0.8	60.6	61.9	0.9	2.2	0.5	3.6	341.3	16.3	7.6	8.3	33.3	9.0	1.0	10.8	82.0	11.8	0.5	65.7	60.5	0.5	2.1	0.3	0.7	205.0	17.9	7.6	8.8	35.1
27.77	23.9	17.80	58.6	80.1	77	2	16.7	37.1	54.9	17.6	3.8	2.7	43.3	108.3	0.4	0.1	1.1	13	48	35	12	31	57	5.3	0.4	8.3	117.0	14.5	2.0	96.7	71.8	0.9	2.4	0.5	3.9	395.0	15.0	7.7	10.0	32.8	11.8	0.9	8.1	73.4	10.7	1.6	57.9	58.1	0.4	3.1	0.3	1.1	193.8	15.8	7.7	8.0	30.1
34.03	8.7	21.02	50.3	68.7	58	1	15.5	36.8	55.9	18.4	2.5	4.6	41.3	141.2	0.4	0.1	0.9	13	48	36	12	31	57	4.4	0.5	10.2	34.1	4.7	1.3	22.4	30.8	0.7	2.5	0.8	4.8	446.4	14.8	7.7	4.3	33.4	4.0	0.4	10.5	58.8	7.6	0.8	38.9	46.6	0.4	2.3	0.5	1.7	316.7	15.7	7.7	6.4	34.2