# help make trig values tables by using while or for loops

• March 9th, 2013, 04:55 PM
my21
help make trig values tables by using while or for loops
My assignment is Write a static void method called printTrigTables that prints the sin, cos, and tan of angles
////between 0 and 360 in increments of 30 degrees. The first column should be the angle size,
//and the next three columns should be the sin, cos, and tan. Use either a while loop or a for
//loop. One problem you will encounter however is that the Math functions for sin, cos, and
//tan take radians, not degrees! So, you must convert your angle to radians first. Here is the
//formula for degree to radian conversion:
//radians = degrees x PI / 180.

public static double degConvert(double degrees){ // converts to degrees
double radians = degrees * (Math.PI/180);
}

For the trig table, can anyone help me make a method, or several encapsulated methods that do the following:

Count from 0 to 360 by 30's, using a loop; convert those numbers into radians using the equation x*pi/180; take all of those values and put them into Math.sin(); print.

Code Java:

```public static void printTrigTables () {   double a1, a2, a3,a4,a5, a6, a7,a8,a9,a10,a11,a12;4 System.out.println ("degree, sin, cos, tan"); double degree; System.out.print("Angle 30 degree "); a1 = 30 * Math.PI/180; System.out.println ("cos(" + a1 + ") is " + Math.acos(a1)); System.out.println ("sin(" + a1 + ") is " + Math.asin(a1)); System.out.println("tan(" + a1 + ") is " + Math.atan(a1)); System.out.print("Angle 60 degree "); a2 = 60 * Math.PI/180; System.out.println("cos(" + a2 + ") is " + Math.acos(a2)) ; System.out.println("sin(" + a2 + ") is " + Math.asin(a2)); System.out.println("tan(" + a2 + ") is " + Math.atan(a2)); System.out.print("Angle 90 degree "); a3 = 90 * Math.PI/180; System.out.println("cos(" + a3 + ") is " + Math.acos(a3)) ; System.out.println("sin(" + a3 + ") is " + Math.asin(a3)); System.out.println("tan(" + a3 + ") is " + Math.atan(a3)); System.out.print("Angle 120 degree "); a4 = 120 * Math.PI/180; System.out.println("cos(" + a4 + ") is " + Math.acos(a4)); System.out.println("sin(" + a4 + ") is " + Math.asin(a4)); System.out.println("tan(" + a4 + ") is " + Math.atan(a4)); System.out.print("Angle 150 degree "); a5 = 150 * Math.PI/180; System.out.println("cos(" + a5 + ") is " + Math.acos(a5)); System.out.println("sin(" + a5 + ") is " + Math.asin(a5)); System.out.println("tan(" + a5 + ") is " + Math.atan(a5)); System.out.print("Angle 180 degree "); a6 = 180 * Math.PI/180; System.out.println("cos(" + a6 + ") is " + Math.acos(a6)); System.out.println("sin(" + a6 + ") is " + Math.asin(a6)); System.out.println("tan(" + a6 + ") is " + Math.atan(a6)); System.out.print("Angle 210 degree "); a7 = 210 * Math.PI/180; System.out.println("cos (" + a7 + ") is " + Math.acos(a7)); System.out.println("sin (" + a7 + ") is " + Math.asin(a7)); System.out.println("tan (" + a7 + ") is " + Math.atan(a7)); System.out.print("Angle 240 degree "); a8 = 240 * Math.PI/180; System.out.println("cos (" + a8 + ") is " + Math.acos(a8)); System.out.println("sin (" + a8 + ") is " + Math.asin(a8)); System.out.println("tan (" + a8 + ") is " + Math.atan(a8)); System.out.print("Angle 270 degree "); a9 = 270 * Math.PI/180; System.out.println("cos (" + a9 + ") is " + Math.acos(a9)); System.out.println("sin (" + a9 + ") is " + Math.asin(a9)); System.out.println("tan (" + a9 + ") is " + Math.atan(a9)); System.out.print("Angle 300 degree "); a10 = (300 * Math.PI)/180; System.out.println("cos (" + a10 + ") is " + Math.acos(a10)); System.out.println("sin (" + a10 + ") is " + Math.asin(a10)); System.out.println("tan (" + a10 + ") is " + Math.atan(a10)); System.out.print("Angle 330 degree "); a11 = (330 * Math.PI)/180; System.out.println("cos (" + a11 + ") is " + Math.acos(a11)); System.out.println("sin (" + a11 + ") is " + Math.asin(a11)); System.out.println("tan (" + a11 + ") is " + Math.atan(a11)); System.out.print("Angle 360 degree "); a12 = (360 * Math.PI)/180; System.out.println("cos (" + a12 + ") is " + Math.acos(a12)); System.out.println("sin (" + a12 + ") is " + Math.asin(a12)); System.out.println("tan (" + a12 + ") is " + Math.atan(a12)); }   }```

I don't know how to put a while or for loop into the program so the 1st column is the angle measure, the 2,3,and 4th columns are the trig values....Help me please!
• March 9th, 2013, 05:00 PM
Norm
Re: help make trig values tables by using while or for loops
You would use a loop to print out the rows. The data on a row (the columns) would be built in a String and printed using a println() statement.

Can you post a sample of the output you are trying to create?
• March 9th, 2013, 05:38 PM
my21
Re: help make trig values tables by using while or for loops
Code Java:

```System.out.println("Degree\tSin\t\tCos\t\tTan"); int i = 0; String str = ""; for (int degree = 0; degree <= 360; degree += 30) { if (i == 0) { str = String.format("%3d\t%6.4f\t\t%6.4f\t\t%6.4f\n", degree, Math.sin(degree * Math.PI / 180), Math.cos(degree * Math.PI / 180), Math.tan(degree * Math.PI / 180)); } else { str = str + "\n" + String.format("%3d\t%6.4f\t\t%6.4f\t\t%6.4f\n", degree, Math.sin(degree * Math.PI / 180), Math.cos(degree * Math.PI / 180), Math.tan(degree * Math.PI / 180));   } i++;   System.out.printf("%3d\t%6.4f\t\t%6.4f\t\t%6.4f\n", degree, Math.sin(degree * Math.PI / 180), Math.cos(degree * Math.PI / 180), Math.tan(degree * Math.PI / 180));   }}}```
My problem now is that I do not understand how %3d\t%6.4f\t\t%6.4f\t\t%6.4f\n makes the trig values work....Also, for the tan values at 90 and 270 are supposed to be undefined, but when I run it, I get a gigantic number.
• March 9th, 2013, 06:27 PM
curmudgeon
Re: help make trig values tables by using while or for loops
It looks like you're borrowing code that you don't yet understand. Where did you get this code from?
• March 9th, 2013, 06:31 PM
Norm
Re: help make trig values tables by using while or for loops
Quote:

I do not understand how %3d\t%6.4f\t\t%6.4f\t\t%6.4f\n makes the trig values work
Those %xxx things are formatting instructions to the format() method of the String class. Read the API doc for that method to see what they mean. The \t is the tab character that is used by the console to move the following String to the next tab position on the screen.
• March 9th, 2013, 06:32 PM
curmudgeon
Re: help make trig values tables by using while or for loops
Note that if you check out the PrintSream#printf(...) API, it will direct you to the java.util.Formatter API. As Norm states, it's all explained there.
• March 9th, 2013, 06:41 PM
my21
Re: help make trig values tables by using while or for loops
This is the output I need, but the tan of 90 and 270 made vary because they are supposed to be undefined. I added the tan into the code.

Code :

```Degree Sin Cos Tan 0 0.0000 1.0000 0.0000 30 0.5000 0.8660 0.5774 60 0.8660 0.5000 1.7321 90 1.0000 0.0000 16331239353195370.0000 120 0.8660 -0.5000 -1.7321 150 0.5000 -0.8660 -0.5774 180 0.0000 -1.0000 -0.0000 210 -0.5000 -0.8660 0.5774 240 -0.8660 -0.5000 1.7321 270 -1.0000 -0.0000 5443746451065123.0000 300 -0.8660 0.5000 -1.7321 330 -0.5000 0.8660 -0.5774 360 -0.0000 1.0000 -0.0000```

Is there a link you can provide?