In: Math
Green |
Red |
NIR |
the correlation matrix is calculated and given as
Green | red | NIR | |
Green | 1 | ||
red | 0.9953 | 1 | |
NIR | 0.9750 | 0.9681 | 1 |
correlation between Green and red is highest=r1=0.9953
r1=(n*sum(xy)-sum(x)*sum(y))/sqrt((n*sum(x2)-(sum(x))2)*(n*sum(y2)-(sum(y))2)=0.9953
and same as for r2 and r3
s.n. | green(x) | red(y) | NIR(z) | x2 | y2 | z2 | xy | xz | yz |
1 | 105 | 128 | 102 | 11025 | 16384 | 10404 | 13440 | 10710 | 10710 |
2 | 108 | 129 | 104 | 11664 | 16641 | 10816 | 13932 | 11232 | 11232 |
3 | 106 | 128 | 103 | 11236 | 16384 | 10609 | 13568 | 10918 | 10918 |
4 | 106 | 129 | 102 | 11236 | 16641 | 10404 | 13674 | 10812 | 10812 |
5 | 105 | 130 | 102 | 11025 | 16900 | 10404 | 13650 | 10710 | 10710 |
6 | 104 | 128 | 101 | 10816 | 16384 | 10201 | 13312 | 10504 | 10504 |
7 | 97 | 115 | 97 | 9409 | 13225 | 9409 | 11155 | 9409 | 9409 |
8 | 104 | 124 | 101 | 10816 | 15376 | 10201 | 12896 | 10504 | 10504 |
9 | 109 | 133 | 106 | 11881 | 17689 | 11236 | 14497 | 11554 | 11554 |
10 | 108 | 134 | 106 | 11664 | 17956 | 11236 | 14472 | 11448 | 11448 |
11 | 106 | 128 | 103 | 11236 | 16384 | 10609 | 13568 | 10918 | 10918 |
12 | 102 | 125 | 99 | 10404 | 15625 | 9801 | 12750 | 10098 | 10098 |
13 | 85 | 95 | 91 | 7225 | 9025 | 8281 | 8075 | 7735 | 7735 |
14 | 93 | 109 | 96 | 8649 | 11881 | 9216 | 10137 | 8928 | 8928 |
15 | 102 | 125 | 100 | 10404 | 15625 | 10000 | 12750 | 10200 | 10200 |
16 | 103 | 124 | 101 | 10609 | 15376 | 10201 | 12772 | 10403 | 10403 |
17 | 104 | 126 | 102 | 10816 | 15876 | 10404 | 13104 | 10608 | 10608 |
18 | 98 | 118 | 98 | 9604 | 13924 | 9604 | 11564 | 9604 | 9604 |
19 | 82 | 89 | 91 | 6724 | 7921 | 8281 | 7298 | 7462 | 7462 |
20 | 82 | 94 | 92 | 6724 | 8836 | 8464 | 7708 | 7544 | 7544 |
21 | 88 | 102 | 92 | 7744 | 10404 | 8464 | 8976 | 8096 | 8096 |
22 | 89 | 101 | 93 | 7921 | 10201 | 8649 | 8989 | 8277 | 8277 |
23 | 95 | 112 | 97 | 9025 | 12544 | 9409 | 10640 | 9215 | 9215 |
24 | 94 | 108 | 99 | 8836 | 11664 | 9801 | 10152 | 9306 | 9306 |
25 | 82 | 89 | 91 | 6724 | 7921 | 8281 | 7298 | 7462 | 7462 |
26 | 81 | 89 | 90 | 6561 | 7921 | 8100 | 7209 | 7290 | 7290 |
27 | 81 | 93 | 90 | 6561 | 8649 | 8100 | 7533 | 7290 | 7290 |
28 | 84 | 95 | 92 | 7056 | 9025 | 8464 | 7980 | 7728 | 7728 |
29 | 89 | 104 | 95 | 7921 | 10816 | 9025 | 9256 | 8455 | 8455 |
30 | 90 | 104 | 98 | 8100 | 10816 | 9604 | 9360 | 8820 | 8820 |
31 | 81 | 90 | 92 | 6561 | 8100 | 8464 | 7290 | 7452 | 7452 |
32 | 81 | 89 | 90 | 6561 | 7921 | 8100 | 7209 | 7290 | 7290 |
33 | 81 | 89 | 89 | 6561 | 7921 | 7921 | 7209 | 7209 | 7209 |
34 | 81 | 90 | 89 | 6561 | 8100 | 7921 | 7290 | 7209 | 7209 |
35 | 83 | 92 | 90 | 6889 | 8464 | 8100 | 7636 | 7470 | 7470 |
36 | 86 | 96 | 94 | 7396 | 9216 | 8836 | 8256 | 8084 | 8084 |
sum | 3375 | 3954 | 3478 | 320145 | 443736 | 337020 | 376605 | 327954 | 327954 |
here we use t-test and statistic would be t =r/sqrt((1—r2)/(n—2)) with df is n-2=16-2=34
for Green and Red the correlation r1=0.9953, t=0.9953/sqrt((1-0.9953*0.9953)/(36-2))=59.93 with 34 df
for Green and NIR the correlation r2=0.975, t=0.975/sqrt((1-0.975*0.975)/(36-2))=25.59 with 34 df
for Green and Red the correlation r3=0.9681 t=0.9681/sqrt((1-0.9681*0.9681)/(36-2))=22.53 with 34 df
typical critical t(0.05,34)=2.03 is less than above calculated t, so there is significant correlation coefficient i.e. r1,r2 and r3 are significant