Vector Component Addition | Zona Land Education

Here's the code that runs the above calculator.

You can change the code, if you like, and then click the following 'Reevaluate code' button. The program will then work as per your changes. Of course, your changes, especially random changes, can introduce errors, miscalculations, and browser crashes. If you need to get things back to their original condition, just reload this page using your browser's reload button.

The intention here is to conveniently show the inner workings of this program so that you understand how the calculation is done.

Click the 'Code' button again to close this section.

onClickCalculateSum = function()
{
	var magnitude1         = 0.0;
	var direction1Deg      = 0.0;
	var direction1Rad      = 0.0;
	var magnitude2         = 0.0;
	var direction2Deg      = 0.0;
	var direction2Rad      = 0.0;
	var x1                 = 0.0;
	var y1                 = 0.0;
	var x2                 = 0.0;
	var y2                 = 0.0;
	var xTotal             = 0.0;
	var yTotal             = 0.0;
	var magnitudeTotal     = 0.0;
	var directionTotalRad  = 0.0;
	var directionTotalDeg  = 0.0;
	var directionTotalNSEW = '';
	var message            = '';

	magnitude1    = parseFloat(window.document.input.magnitude1.value);
	direction1Deg = parseFloat(window.document.input.direction1Deg.value);
	magnitude2    = parseFloat(window.document.input.magnitude2.value);
	direction2Deg = parseFloat(window.document.input.direction2Deg.value);

	if(magnitude1 <= 0.0)
	{
		alert('Please enter a positive number\nfor the first magnitude.');

		return;
	}

	if(direction1Deg < 0.0 || direction1Deg > 90.0)
	{
		alert('Please enter a number between 0.0 and 90.0 inclusive\nfor the first direction.');

		return;
	}

	if(magnitude2 <= 0.0)
	{
		alert('Please enter a positive number\nfor the second magnitude.');

		return;
	}

	if(direction2Deg < 0.0 || direction2Deg > 90.0)
	{
		alert('Please enter a number between 0.0 and 90.0 inclusive\nfor the second direction.');

		return;
	}

	direction1Rad = direction1Deg * (Math.PI / 180.0);
	direction2Rad = direction2Deg * (Math.PI / 180.0);


	if(window.document.input.direction1[0].checked)
	{
		x1 = magnitude1 * Math.cos(direction1Rad);
		x1 = -x1;

		y1 = magnitude1 * Math.sin(direction1Rad);
	}
	else if(window.document.input.direction1[1].checked)
	{
		x1 = magnitude1 * Math.sin(direction1Rad);
		x1 = -x1;

		y1 = magnitude1 * Math.cos(direction1Rad);
	}
	else if(window.document.input.direction1[2].checked)
	{
		x1 = magnitude1 * Math.cos(direction1Rad);

		y1 = magnitude1 * Math.sin(direction1Rad);
	}
	else if(window.document.input.direction1[3].checked)
	{
		x1 = magnitude1 * Math.sin(direction1Rad);

		y1 = magnitude1 * Math.cos(direction1Rad);
	}
	else if(window.document.input.direction1[4].checked)
	{
		x1 = magnitude1 * Math.cos(direction1Rad);
		x1 = -x1;

		y1 = magnitude1 * Math.sin(direction1Rad);
		y1 = -y1;
	}
	else if(window.document.input.direction1[5].checked)
	{
		x1 = magnitude1 * Math.sin(direction1Rad);
		x1 = -x1;

		y1 = magnitude1 * Math.cos(direction1Rad);
		y1 = -y1;
	}
	else if(window.document.input.direction1[6].checked)
	{
		x1 = magnitude1 * Math.cos(direction1Rad);

		y1 = magnitude1 * Math.sin(direction1Rad);
		y1 = -y1;
	}
	else if(window.document.input.direction1[7].checked)
	{
		x1 = magnitude1 * Math.sin(direction1Rad);

		y1 = magnitude1 * Math.cos(direction1Rad);
		y1 = -y1;
	}
	else
	{
		alert('Please check a direction for vector 1.');
	}


	if(window.document.input.direction2[0].checked)
	{
		x2 = magnitude2 * Math.cos(direction2Rad);
		x2 = -x2;

		y2 = magnitude2 * Math.sin(direction2Rad);
	}
	else if(window.document.input.direction2[1].checked)
	{
		x2 = magnitude2 * Math.sin(direction2Rad);
		x2 = -x2;

		y2 = magnitude2 * Math.cos(direction2Rad);
	}
	else if(window.document.input.direction2[2].checked)
	{
		x2 = magnitude2 * Math.cos(direction2Rad);

		y2 = magnitude2 * Math.sin(direction2Rad);
	}
	else if(window.document.input.direction2[3].checked)
	{
		x2 = magnitude2 * Math.sin(direction2Rad);

		y2 = magnitude2 * Math.cos(direction2Rad);
	}
	else if(window.document.input.direction2[4].checked)
	{
		x2 = magnitude2 * Math.cos(direction2Rad);
		x2 = -x2;

		y2 = magnitude2 * Math.sin(direction2Rad);
		y2 = -y2;
	}
	else if(window.document.input.direction2[5].checked)
	{
		x2 = magnitude2 * Math.sin(direction2Rad);
		x2 = -x2;

		y2 = magnitude2 * Math.cos(direction2Rad);
		y2 = -y2;
	}
	else if(window.document.input.direction2[6].checked)
	{
		x2 = magnitude2 * Math.cos(direction2Rad);

		y2 = magnitude2 * Math.sin(direction2Rad);
		y2 = -y2;
	}
	else if(window.document.input.direction2[7].checked)
	{
		x2 = magnitude2 * Math.sin(direction2Rad);

		y2 = magnitude2 * Math.cos(direction2Rad);
		y2 = -y2;
	}
	else
	{
		alert('Please check a direction for vector 2.');
	}

	xTotal = x1 + x2;
	yTotal = y1 + y2;

	magnitudeTotal    = Math.sqrt(xTotal * xTotal + yTotal * yTotal);
	if(xTotal != 0.0)
	{
		directionTotalRad = Math.atan(Math.abs(yTotal) / Math.abs(xTotal));
		directionTotalDeg = directionTotalRad * (180.0 / Math.PI);

		if(xTotal >= 0.0 && yTotal >= 0.0)
		{
			directionTotalNSEW = 'N of E';
		}
		else if(xTotal <= 0.0 && yTotal >= 0.0)
		{
			directionTotalNSEW = 'N of W';
		}
		else if(xTotal <= 0.0 && yTotal <= 0.0)
		{
			directionTotalNSEW = 'S of W';
		}
		else // if(xTotal >= 0.0 && yTotal <= 0.0)
		{
			directionTotalNSEW = 'S of E';
		}
	}
	else
	{
	}

	message  = 'First vector x-component: ' + x1 + '\n';
	message += 'First vector y-component: ' + y1 + '\n';
	message += 'Second vector x-component: ' + x2 + '\n';
	message += 'Second vector y-component: ' + y2 + '\n\n';
	message += 'Total x-component: ' + xTotal + '\n';
	message += 'Total y-component: ' + yTotal + '\n\n';
	message += 'Total magnitude: ' + magnitudeTotal + '\n';
	message += 'Total direction: ' + directionTotalDeg + ' degrees ' + directionTotalNSEW + '\n';

	alert(message);
};

First Vector
Magnitude:
Direction (degrees):
N of W	W of N	N of E	E of N
S of W	W of S	S of E	E of S

Second Vector
Magnitude:
Direction (degrees):
N of W	W of N	N of E	E of N
S of W	W of S	S of E	E of S