From b43eccd4cffed5bd1017c5821524fb6e49202f78 Mon Sep 17 00:00:00 2001
From: Sandeep Gupta
Date: Sun, 18 Jun 2017 23:55:40 +0530
Subject: First commit

---
 .../scilabcode/mainfunction.sci                    | 56 ++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 2.3-1/tests/unit_tests/test001_LinearRegression/scilabcode/mainfunction.sci

(limited to '2.3-1/tests/unit_tests/test001_LinearRegression/scilabcode')

diff --git a/2.3-1/tests/unit_tests/test001_LinearRegression/scilabcode/mainfunction.sci b/2.3-1/tests/unit_tests/test001_LinearRegression/scilabcode/mainfunction.sci
new file mode 100644
index 00000000..13624cfb
--- /dev/null
+++ b/2.3-1/tests/unit_tests/test001_LinearRegression/scilabcode/mainfunction.sci
@@ -0,0 +1,56 @@
+//SCI2C: DEFAULT_PRECISION= DOUBLE
+
+function mainfunction()
+
+// Knowing that 
+// (1) P * (V^gamma) = C
+// Where
+// P = Pressure
+// V = Volume
+// gamma,C = constants depending on the particular gas used.
+// (2) log10(P) = log10(C) - gamma*log10(V)
+// (3) x = log10(V) 
+// (4) y = log10(P)
+// than (2) becomes:
+// y = a + b*x;
+// Where
+// a = log10(C)
+// b = -gamma
+// Then thanks to this transformation it is possible to perform 
+// a linear regression to estimate gamma and C!
+
+Volume   = [54.3 61.8 72.4 88.7 118.6 194.0];
+Pressure = [61.2 49.5 37.6 28.4 19.2 10.1];
+x = log10(Volume);
+y = log10(Pressure);
+
+a = (sum(y)*sum(x.^2)-sum(x)*sum(x.*y))./(length(x)*sum(x.^2)-sum(x).*sum(x));
+b = (length(x)*sum(x.*y)-sum(x)*sum(y))./(length(x)*sum(x.^2)-sum(x).*sum(x));
+
+// Other way to compute a and b
+beq = sum((x-mean(x)).*(y-mean(y)))./sum((x-mean(x)).^2);
+aeq = mean(y)-mean(x)*beq;
+
+C = 10 .^a;
+gamma = -b;
+
+disp('C')
+disp(C)
+
+disp('gamma');
+disp(gamma);
+
+disp('a');
+disp(a)
+disp('aeq');
+disp(aeq)
+
+disp('b');
+disp(b)
+disp('beq');
+disp(beq)
+
+ //plot(Volume,Pressure);
+ //plot(Volume,(C ./(Volume.^gamma)),'r')
+endfunction
+
-- 
cgit