Improved formatting of number axis. Increased precision of values sent over serial

Author: devinaconley

listener/Graph.java

@@ -1,4 +1,5 @@
 import processing.core.PApplet;
+import java.text.DecimalFormat;
 
 class Graph
 {
@@ -221,9 +222,12 @@ private void DrawTicks( double xScale, double xOffset, double yScale, double yOf
 	for ( float tempY = this.posY + tickOffset; tempY <= this.posY + this.height - tickOffset;
 	     tempY += tickInterval )
 	{
-	    float val = (float) ( ( ( yOffset + this.posY ) - (double)tempY ) / yScale ); 
+	    float val = (float) ( ( ( yOffset + this.posY ) - (double)tempY ) / yScale );
+	    int n = GetDecimalPlaces( val );
+	    String fmt = "%" + Integer.toString( 1 + SIG_DIGITS - n ) + "." + Integer.toString( n ) + "g";
+	    this.parent.println( fmt );
 	    this.parent.line( tempX, tempY, tempX + TICK_LEN, tempY );
-	    this.parent.text( Float.toString( val ), tempX + TICK_LEN + 5, tempY );
+	    this.parent.text( String.format( fmt, val ), tempX + TICK_LEN + 5, tempY );
 	}
 
 	// x-axis
@@ -236,11 +240,32 @@ private void DrawTicks( double xScale, double xOffset, double yScale, double yOf
 	{
 	    float val = (float) ( ( (double)tempX + xOffset - this.posX ) / xScale ); 
 	    this.parent.line( tempX, tempY, tempX, tempY + TICK_LEN );
-	    this.parent.text( Float.toString( val ), tempX, tempY - 5 );
+	    if ( this.xvy )
+	    {
+		int n = GetDecimalPlaces( val );
+		String fmt = "%" + Integer.toString( 1 + SIG_DIGITS - n ) + "." + Integer.toString( n ) + "g";
+		this.parent.text( String.format( fmt, val ), tempX, tempY - 5 );
+	    }
+	    else
+	    {
+		this.parent.text( String.format( "%d", (int)val ), tempX, tempY - 5 );		
+	    }
 	}	
 
     }
 
+    private int GetDecimalPlaces( float value )
+    {
+	int n = SIG_DIGITS;
+	int d = 1;	
+	while ( n > 0 && Math.round( Math.abs( value / d ) ) > 0 )
+	{
+	    n--;
+	    d *= 10;
+	}
+	return n;
+    }
+
     private void CheckExtremes()
     {
 	// Check new values
@@ -348,5 +373,5 @@ else if ( this.data[i][j][0] > this.extremes[1] ) // (max)
     private static final int TICK_LEN = 6;
     private static final int NUM_TICKS = 5;
     private static final float PT_SZ = 1.5f;
-
-}
+    private static final int SIG_DIGITS = 3;
+}

plotter/Plotter.cpp

@@ -201,11 +201,14 @@ void Plotter::Graph::Plot()
     Serial.print( xvy ); Serial.print( INNER_KEY );
     Serial.print( pointsDisplayed ); Serial.print( INNER_KEY );
     Serial.print( size ); Serial.print( INNER_KEY );
+
+    char val[15];
     for (int i = 0; i < size; i++)
     {
 	Serial.print( wrappers[i].GetLabel() ); Serial.print( INNER_KEY );
 	Serial.print( wrappers[i].GetColor() ); Serial.print( INNER_KEY );
-	Serial.print( wrappers[i].GetValue() ); Serial.print( INNER_KEY );
+	dtostrf( wrappers[i].GetValue(), 1, 7, val );
+	Serial.print( val ); Serial.print( INNER_KEY );
     }
 }
 

plotter/examples/set_colors/set_colors.ino

@@ -26,11 +26,12 @@ void setup()
     // Set variable colors of graph with index 0 to pink and orange
     p.SetColor( 0, "pink", "orange" );
     p.SetColor( 1, "cyan" );
+
 }
 
 void loop() {
-    x = 10*sin( 2.0*PI*( millis() / 5000.0 ) );
-    y = 10*cos( 2.0*PI*( millis() / 5000.0 ) );
-    
+    x = 0.0009*sin( 2.0*PI*( millis() / 5000.0 ) );
+    y = 90000*cos( 2.0*PI*( millis() / 5000.0 ) );
+
     p.Plot(); // usually called within loop()
 }