Zero values in logarithmic mode draw off chart top?

• March 16, 2020 at 7:05 am #28653
  
  m-the-hoff

  If you paste the following into the “try it” edit box, notice that any zero value renders as a # of the top of the chart.

  The only solution I’ve found is to set all zeros to 1. Am I missing something or is this a bug?

  CanvasJS.Chart(“chartContainer”,{
  axisY: { logarithmic: true },
  data: [{
  type: “line”,
  dataPoints: [{y:10},{y:0},{y:50},{y:65},{y:150},{y:400},{y:950},{y:4500},{y:10000}]
  }] });

  Thank you!
  Michael

  March 16, 2020 at 6:38 pm #28661
  
  Vishwas R

  Michael,

  A logarithmic axis can only plot positive values. There simply is no way to put negative values or zero on a logarithmic axis.

  Fundamental: If 10L = Z, then L is the logarithm (base 10) of Z. If L is a negative value, then Z is a positive fraction less than 1.0. If L is zero, then Z equals 1.0. If L is greater than 0, then Z is greater than 1.0. Note that there no value of L will result in a value of Z that is zero or negative. Logarithms are simply not defined for zero or negative numbers.

  —
  Vishwas R
  Team CanvasJS