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Format code with prettier (#3375)

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acbin
2022-10-03 17:23:00 +08:00
committed by GitHub
parent 32b9b11ed5
commit e96f567bfc
464 changed files with 11483 additions and 6189 deletions
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76
src/main/java/com/thealgorithms/maths/EulerMethod.java
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@ -26,24 +26,40 @@ public class EulerMethod {
BiFunction<Double, Double, Double> exampleEquation1 = (x, y) -> x;
ArrayList<double[]> points1 = eulerFull(0, 4, 0.1, 0, exampleEquation1);
assert points1.get(points1.size() - 1)[1] == 7.800000000000003;
points1.forEach(
point -> System.out.println(String.format("x: %1$f; y: %2$f", point[0], point[1])));
points1.forEach(point ->
System.out.println(
String.format("x: %1$f; y: %2$f", point[0], point[1])
)
);
// example from https://en.wikipedia.org/wiki/Euler_method
System.out.println("\n\nexample 2:");
BiFunction<Double, Double, Double> exampleEquation2 = (x, y) -> y;
ArrayList<double[]> points2 = eulerFull(0, 4, 0.1, 1, exampleEquation2);
assert points2.get(points2.size() - 1)[1] == 45.25925556817596;
points2.forEach(
point -> System.out.println(String.format("x: %1$f; y: %2$f", point[0], point[1])));
points2.forEach(point ->
System.out.println(
String.format("x: %1$f; y: %2$f", point[0], point[1])
)
);
// example from https://www.geeksforgeeks.org/euler-method-solving-differential-equation/
System.out.println("\n\nexample 3:");
BiFunction<Double, Double, Double> exampleEquation3 = (x, y) -> x + y + x * y;
ArrayList<double[]> points3 = eulerFull(0, 0.1, 0.025, 1, exampleEquation3);
BiFunction<Double, Double, Double> exampleEquation3 = (x, y) ->
x + y + x * y;
ArrayList<double[]> points3 = eulerFull(
0,
0.1,
0.025,
1,
exampleEquation3
);
assert points3.get(points3.size() - 1)[1] == 1.1116729841674804;
points3.forEach(
point -> System.out.println(String.format("x: %1$f; y: %2$f", point[0], point[1])));
points3.forEach(point ->
System.out.println(
String.format("x: %1$f; y: %2$f", point[0], point[1])
)
);
}
/**
@ -57,14 +73,20 @@ public class EulerMethod {
* @return The next y-value.
*/
public static double eulerStep(
double xCurrent,
double stepSize,
double yCurrent,
BiFunction<Double, Double, Double> differentialEquation) {
double xCurrent,
double stepSize,
double yCurrent,
BiFunction<Double, Double, Double> differentialEquation
) {
if (stepSize <= 0) {
throw new IllegalArgumentException("stepSize should be greater than zero");
throw new IllegalArgumentException(
"stepSize should be greater than zero"
);
}
double yNext = yCurrent + stepSize * differentialEquation.apply(xCurrent, yCurrent);
double yNext =
yCurrent +
stepSize *
differentialEquation.apply(xCurrent, yCurrent);
return yNext;
}
@ -81,29 +103,35 @@ public class EulerMethod {
* equation.
*/
public static ArrayList<double[]> eulerFull(
double xStart,
double xEnd,
double stepSize,
double yStart,
BiFunction<Double, Double, Double> differentialEquation) {
double xStart,
double xEnd,
double stepSize,
double yStart,
BiFunction<Double, Double, Double> differentialEquation
) {
if (xStart >= xEnd) {
throw new IllegalArgumentException("xEnd should be greater than xStart");
throw new IllegalArgumentException(
"xEnd should be greater than xStart"
);
}
if (stepSize <= 0) {
throw new IllegalArgumentException("stepSize should be greater than zero");
throw new IllegalArgumentException(
"stepSize should be greater than zero"
);
}
ArrayList<double[]> points = new ArrayList<double[]>();
double[] firstPoint = {xStart, yStart};
double[] firstPoint = { xStart, yStart };
points.add(firstPoint);
double yCurrent = yStart;
double xCurrent = xStart;
while (xCurrent < xEnd) {
// Euler method for next step
yCurrent = eulerStep(xCurrent, stepSize, yCurrent, differentialEquation);
yCurrent =
eulerStep(xCurrent, stepSize, yCurrent, differentialEquation);
xCurrent += stepSize;
double[] point = {xCurrent, yCurrent};
double[] point = { xCurrent, yCurrent };
points.add(point);
}