TanTest.java

package jscl.math.function.trigonometric;

import jscl.AngleUnit;
import jscl.JsclMathEngine;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

/**
 * User: serso
 * Date: 1/7/12
 * Time: 4:03 PM
 */
public class TanTest {

    @Test
    public void testIntegrate() throws Exception {
        final JsclMathEngine me = JsclMathEngine.getInstance();

        // todo serso: uncomment after variable modification issue fixed
/*		Assert.assertEquals("-2*ln(2)-ln(cos(x))", me.simplify("∫(tan(x), x)"));
        Assert.assertEquals("-(2*ln(2)+ln(cos(x*π)))/π", me.simplify("∫(tan(π*x), x)"));

		Assert.assertEquals("-0.015308831465985804", me.evaluate("ln(cos(10))"));
		Assert.assertEquals("-0.1438410362258904", me.evaluate("ln(cos(30))"));
		Assert.assertEquals("0.12853220475990468", me.evaluate("∫ab(tan(x), x, 10, 30)"));*/

        try {
            me.setAngleUnits(AngleUnit.rad);
            assertEquals("-2*ln(2)-ln(cos(x))", me.simplify("∫(tan(x), x)"));
            assertEquals("-(2*ln(2)+ln(cos(x*π)))/π", me.simplify("∫(tan(π*x), x)"));
            assertEquals("-0.015308831465986", me.evaluate("ln(cos(10*π/180))"));
            assertEquals("-0.14384103622589", me.evaluate("ln(cos(30*π/180))"));
            assertEquals("0.128532204759905", me.evaluate("∫ab(tan(x), x, 10*π/180, 30*π/180)"));
        } finally {
            me.setAngleUnits(AngleUnit.deg);
        }
    }

    @Test
    public void testBoundaryConditions() throws Exception {
        final JsclMathEngine me = JsclMathEngine.getInstance();
        assertEquals("-∞", me.evaluate("tan(-450)"));
        assertEquals("0", me.evaluate("tan(-360)"));
        assertEquals("-∞", me.evaluate("tan(-270)"));
        assertEquals("0", me.evaluate("tan(-180)"));
        assertEquals("-∞", me.evaluate("tan(-90)"));
        assertEquals("0", me.evaluate("tan(0)"));
        assertEquals("∞", me.evaluate("tan(180/2)"));
        assertEquals("∞", me.evaluate("tan(45 + 45)"));
        assertEquals("∞", me.evaluate("tan(30*3)"));
        assertEquals("∞", me.evaluate("tan(90)"));
        assertEquals("0", me.evaluate("tan(180)"));
        assertEquals("∞", me.evaluate("tan(270)"));
        assertEquals("0", me.evaluate("tan(360)"));
        assertEquals("∞", me.evaluate("tan(450)"));
    }
}