fix zoom scaling problem : min/max value of axis can be inverted when there are negative values

yafitsv/views/olqv.ejs

@@ -1575,8 +1575,14 @@ var SAMPPNGPublishControl = (function (Control) {
                                 summedPixelsSpectrumChart.xAxis[0].setExtremes( summedPixelsSpectrumChart.xAxis[0].dataMin,
                                                                                 summedPixelsSpectrumChart.xAxis[0].dataMax);
                             }else{
-                                let minval = f2v(event.min * 1e9, _restfreq)/1e3;
-                                let maxval = f2v(event.max * 1e9, _restfreq)/1e3;
+                                let minval = Math.round(f2v(event.min * 1e9, _restfreq)/1e3);
+                                let maxval = Math.round(f2v(event.max * 1e9, _restfreq)/1e3);
+                                //exchange min/max if min > max
+                                if(minval > maxval){
+                                    let tmp = minval;
+                                    minval = maxval;
+                                    maxval = tmp;
+                                }
                                 summedPixelsSpectrumChart.xAxis[0].setExtremes(minval,maxval);
                             }                            
                         },