Cango Axes User Guide

Syntax:

axs = new Axes(xmin, xmax, ymin, ymax [, options])

Description:

Creates a set of Cartesian coordinate (X, Y) axes.

Parameters:

Optional Properties:

Examples:

function drawAxesTest(cvsID)
{
  var gc = new Cango(cvsID),
      xmin = -0.01, xmax = 0.025,
      ymin = -300, ymax = 600;

  gc.gridboxPadding(8);
  gc.setWorldCoordsRHC(xmin, ymin, xmax-xmin, ymax-ymin);
  gc.drawAxes(xmin, xmax, ymin, ymax, {
    xOrigin: 0,
    yOrigin: 0,
    xtickDirection: "cross",
    xUnits:"m",
    yUnits:"V",
    xLabel:"Distance",
    yLabel:"Potential" });
}

Syntax:

bxaxs = new drawBoxAxes(xmin, xmax, ymin, ymax [, options])

Description:

Creates a set of X, Y axes in the shape of a box.

Parameters:

Optional Properties:

Example:

function drawBoxAxesTest(cvsID)
{
  var g = new Cango(cvsID),
      data = [],
      i;

  g.fillGridbox("#303a30");
  g.gridboxPadding(12, 8, 3, 8);
  g.setWorldCoordsRHC(0, -10, 1200, 20);

  g.drawBoxAxes(0, 1200, -10, 10, {
    xUnits:"Hz", 
    yUnits:"dB", 
    title:"REAL"});
  for (i=0; i<=200; i++)
  {
    data.push(i*6, 5*Math.sin(i/6));
  }
  g.drawPath(data, {strokeColor:'#c0e0ff'});
}

Syntax:

xax = new Xaxis(xmin, xmax [, options])

Description:

Creates an X axis suitable as an addition to an existing set of axes so that addition data sets may be plotted with a sutiable axis.

Parameters:

Optional Properties:

Syntax:

xax = new Yaxis(xmin, xmax [, options])

Description:

Creates an Y axis suitable as an addition to an existing set of axes so that addition data sets may be plotted with a sutiable axis.

Parameters:

Optional Properties:

Example:

function drawJournalAxes(cvsID)
{
var gc = new Cango(cvsID),
    xmin = 0, xmax = 0.025,
    ymin = 0, ymax = 600;

gc.gridboxPadding(16, 10, 5, 5);
gc.setWorldCoordsRHC(xmin, ymin, xmax-xmin, ymax-ymin);

const axs = new Axes(xmin, xmax, ymin, ymax, {
  xOrigin: 0,
  yOrigin: 0,
  xUnits:"m",
  yUnits:"V",
  xLabel:"Distance",
  yLabel:"Potential",
  fontFamily:"Times" });
const xax = new Xaxis(xmin, xmax, {
  yOrigin: ymax,
  xtickDir: "down",
  xLabelInterval: 0 });
gc.render(xax);

const yax = new Yaxis(ymin, ymax, {
  xOrigin: xmax,
  ytickDir: "left",
  yLabelInterval: 0,
  fontColor: "blacK" });
gc.render(yax);
}

Syntax:

cgo.drawAxes(xmin, xmax, ymin, ymax [, options]);

Description:

A wrapper function to simplify drawing a single instance of an Axes object. The drawAxes method creates an Axes object passing the arguments unchanged to the constructor and then renders it to the canvas.

Parameters:

Syntax:

cgo.drawBoxAxes(xmin, xmax, ymin, ymax [, options]);

Description:

A wrapper function to simplify drawing a single instance of an BoxAxes object. The drawBoxAxes method creates an BoxAxes object passing the arguments unchanged to the constructor and then renders it to the canvas.

Parameters:

Syntax:

var str = toEngFixed(val, decPlaces);

Description:

Converts the value val to engineering notation, i.e. mantissa and exponent where the exponent is restricted to values that are multiples of 1000. The string returned denotes the exponent by the standard single letter values µ, m, k, M, G etc. All mantissa values are expressed in the range 1 to 1000 with the number of decimal places set by the decPlaces parameter. The result is rounded to the decPlaces decimal places with no trailing zeroes are removed.

Parameters:

val:Number - The value to be formatted.

decPlaces:Number - the number of decimal places in the mantissa.

Returns:

String - The formatted string version of val.

Examples:

toEngFixed(1200.0, 3) returns "1.200k".
toEngFixed(0.012345, 2) returns "12.35m".

Syntax:

var str = toEngPrec(val, sigFigs, showPlus);

Description:

Converts the value val to engineering notation, i.e. mantissa and exponent where the exponent is restricted to values that are multiples of 1000. The result is then rounded to a precision of sigFigs significant figures which must be 3 or greater. The string returned denotes the exponent by the standard single letter values p, n, µ, m, k, M, G. All mantissa values are expressed in the range 1 to <1000. The returned string has a fixed length regardless of whether the number is negative or requires a decimal radix.

Parameters:

val: Number - The value to be formatted.

sigFigs: Number - the number of significant figures in the mantissa. Default value is 3

showPlus: Boolean - if evaluating true and the number is positive, a "+" sign is prepended to the return string.

Returns:

String - The formatted string version of val.

Examples:

toEngPrec(1234.5678, 5)   returns  " 1.2346k".
toEngPrec(-1234.5678, 5)  returns  "-1.2346k".
toEngPrec(0.012345, 3)       returns " 12.3m".
toEngPrec(0.012345, 3, true) returns "+12.3m".
toEngPrec(123.45, 3)         returns "  123 ".

Syntax:

var obj = toEngNotation(val, exponent);

Description:

Converts the value val to engineering notation, i.e. mantissa and exponent where the exponent is restricted to values that are multiples of 1000. The result is then rounded to 2 decimal places (suitable for labelling graphs). An object is returned with the numeric and string versions of the value and exponent as properties. The optional parameter 'exponent' allows a preset value of the exponent to be used in the value conversion. The string version of the exponent returned will be the standard single letter values p, n, µ, m, k, M, G. All mantissa values are expressed in the range 1 to <1000.

Parameters:

val: Number - The value to be formatted.

exponent: Number - An optional pre-calculated exponent to be used in the conversion. If undefined or not a multiple of 3 the exponent is ignored and a new exponent calculated.

Returns:

Object - The formatted numeric and string versions of val converted to engineering notation. The property names are: {man: , exp, manStr: , expStr: }.

Examples:

toEngNotation(1234.5678)  returns { man: 1.23, manStr: "1.23", exp: 3, expStr: "k" }.
toEngNotation(0.012345)    returns { man: 12.35, manStr: "12.35", exp: -3, expStr: "m" }.
toEngNotation(0.012345, 0) returns { man: 0.01, manStr: "0.01", exp: 0, expStr: "" }.
toEngNotation(123.45)      returns { man: 123.45, manStr: "123.45", exp: 0, expStr: "" }.
If 'exponent' parameter is not a multiple of 3, it is ignored eg.
toEngNotation(1234.5678, 2) returns { man: 1.23, manStr: "1.23", exp: 3, expStr: "k" } 

Syntax:

var obj = toSciNotation(val [, exponent]);

Description:

Converts the value val to scientific notation, i.e. mantissa and exponent where the exponent is a power of 10. The result is then rounded to 2 decimal places (suitable for labelling graphs). An object is returned with the numeric and string versions of the mantissa and exponent.

Parameters:

val: Number - The value to be formatted.

exponent: Number - An optional pre-set exponent to be used in the conversion. If undefined the exponent is calculated to leave one significant digit in front of the decimal place.

Returns:

Object - The formatted numeric and string versions of val converted to scientific notation. The property names are: {man: , manStr: , exp: , expStr: }.

Examples:

toSciNotation(12345.678)       returns { man: 1.23, manStr: "1.23", exp: 4, expStr: "4" }.
toSciNotation(-12.345678)      returns { man: -1.23, manStr: "-1.23", exp: 1, expStr: "1" }.
toSciNotation(0.012345, 0)     returns { man: 0.01, manStr: "0.01", exp: 0, expStr: "0" }.
toSciNotation(0.000012345)     returns { man: 1.23, manStr: "1.23", exp: -5, expStr: "-5" }.
toSciNotation(0.000012345, -4) returns { man: 0.12, manStr: "0.12", exp: -4, expStr: "-4" }.

Syntax:

var str = sprintf(format, arg1, arg2 ...);

Description:

This JavaScript implementation of the 'sprintf' utility was originally written by Ash Searle (2007/03/printf-sprintf/) and enhanced by Kevin van Zonneveld (http://kevin.vanzonneveld.net).

The 'format' string is composed of ordinary characters (excluding %) and optional conversion specifications. Ordinary characters are copied directly to the result. Each conversion specification consists of a percent sign (%), followed by one or more of these elements, flags, width, precision and type specifier. Each conversion specifications takes an argument in turn from those following 'format' and converts it a substring which replaces the specifier in the output.

Parameters:

  %[flags][width][.precision]type_specifier

Returns:

String - The formatted version of format with specifiers replaced with arguments in the order passed.

Examples:

var str = sprintf("pi = %4.2f", Math.PI); //  returns "pi = 3.14".