56 lines
1.9 KiB
V
56 lines
1.9 KiB
V
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import math
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struct LinearResult {
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r2 f64
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intercept f64
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slope f64
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dependent_variable_means f64
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independent_variable_means f64
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}
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fn linearrelationship(independent_variable []int, dependent_variable []int) LinearResult {
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// Objective :
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// Find what is the linear relationship between two dataset X and Y?
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// x := independent variable
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// y := dependent variable
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mut sum_r2_x := 0
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mut sum_r2_y := 0
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mut sum_xy := 0
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mut sum_x := 0
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mut sum_y := 0
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for i in independent_variable {
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sum_x += i
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sum_r2_x += i * i
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}
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for yi in dependent_variable {
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sum_y += yi
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sum_r2_y += yi * yi
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}
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x_means := sum_x / independent_variable.len
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y_means := sum_y / dependent_variable.len
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for index, x_value in independent_variable {
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sum_xy += x_value * dependent_variable[index]
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}
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// /Slope = (∑y)(∑x²) - (∑x)(∑xy) / n(∑x²) - (∑x)²
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slope_value := f64((sum_y * sum_r2_x) - (sum_x * sum_xy)) / f64((sum_r2_x * independent_variable.len) - (sum_x * sum_x))
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// /Intercept = n(∑xy) - (∑x)(∑y) / n(∑x²) - (∑x)²
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intercept_value := f64((independent_variable.len * sum_xy) - (sum_x * sum_y)) / f64((independent_variable.len * sum_r2_x) - (sum_x * sum_x))
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// Regression equation = Intercept + Slope x
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// R2 = n(∑xy) - (∑x)(∑y) / sqrt([n(∑x²)-(∑x)²][n(∑y²)-(∑y)²]
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r2_value := f64((independent_variable.len * sum_xy) - (sum_x * sum_y)) / math.sqrt(f64((sum_r2_x * independent_variable.len) - (sum_x * sum_x)) * f64((sum_r2_y * dependent_variable.len) - (sum_y * sum_y)))
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return LinearResult{
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r2: r2_value
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intercept: intercept_value
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slope: slope_value
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independent_variable_means: x_means
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dependent_variable_means: y_means
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}
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}
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fn main() {
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independent_variable := [4, 5, 6, 7, 10]
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dependent_variable := [3, 8, 20, 30, 12]
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result := linearrelationship(independent_variable, dependent_variable)
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println(result)
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}
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