First success post

03 May 2020 - viridi - Sparisoma Viridi

Try to get some marks in document, such as Figure \ptref{graph-line-points} and fortunately how in works with \ptref{graph-points} can no be explained.

Today we has accomplished in using MathJax and syntax highlighting using Rouge in Jekyll. And also introduction to pText in drawing a xy-chart using canvas through JavaScript.

We can have a graph of line

{ // xy-chart label: "graph-line", caption: "Graph with line", background: "#fffafa", width: 300, height: 150, data: { x: [0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300], y: [0, 65, 100, 130, 145, 150, 140, 120, 90, 50, 0], }, type : "line", color: { line: "#f88", point: "#e00", }, }

or points

{ // xy-chart label: "graph-points", caption: "Graph with points", background: "#fafffa", width: 300, height: 150, data: { x: [0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300], y: [0, 65, 100, 130, 145, 150, 140, 120, 90, 50, 0], }, type : "point", color: { line: "#8f8", point: "#0e0", }, }

or event both

{ // xy-chart label: "graph-line-points", caption: "Graph with line and points", background: "#fafaff", width: 300, height: 150, data: { x: [0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300], y: [0, 65, 100, 130, 145, 150, 140, 120, 90, 50, 0], }, type : "line-point", color: { line: "#88f", point: "#00e", }, }

Figures \ptref{graph-line}, \ptref{graph-points}, and \ptref{graph-line-points} are created with only a few lines of code. It can be seen that figure \ptref{graph-line-points} has both property of figures \ptref{graph-line} and \ptref{graph-points} in drawing the results.

A quadratic equation is simply

\begin{equation} \label{eq:equation-quadratic} y = ax^2 + bx + c, \end{equation}

whose roots can be obtained from

\begin{equation} \label{eq:equation-quadratic-roots} x_{1,2} = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}. \end{equation}

Implementation of equations \eqref{eq:equation-quadratic} and \eqref{eq:equation-quadratic-roots} in JavaScript can be as follow

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function roots() {
	// Get equation parameters
	var eqn = arguments[0];
	var a = eqn.a;
	var b = egn.b;
	var c = eqn.c;
	
	// Calculate discriminant
	var D = b * b - 4 * a * c;
	
	// Calculate roots using 
	var x1 = (-b + Math.sqrt(D)) / (2 * a);
	var x2 = (-b - Math.sqrt(D)) / (2 * a);
	
	return [x1, x2];
}

where equation \eqref{eq:equation-quadratic-roots} is known as quadratic formula.