Color an object based on strings in a table

Polarbaer

I would like to assign the colors of dots in a scatter plot based on the strings from a column in a table. I've simplified the code in the example below. I want to color the dot red if the string from column "educ" is equal to "Type A" and color it green if it is equal to any other value.

The code I've used which does not work is:

color dot;

void draw()
{
  background(255);

  int numRows = dataTable.getRowCount();

  for (int row=0; row<numRows; row++)
  {
    float X = dataTable.getFloat(row, "X");
    float Y   = dataTable.getFloat(row, "Y");

    float xPos        = map(discIncome, 0, 2000, 0, width);
    float yPos        = map(consumed, 0, 2000, height, 0);

    String colorData = dataTable.getString(row,"educ");

    if (colorData == "Type A") 
    {
      color dot = color(255,0,0);
    }
    else
    {
      color dot = color(0,255,0);
    }

      fill(dot);
      ellipse(xPos, yPos, 5, 5);
  }
}

Any help would be appreciated.

GoToLoop

http://forum.processing.org/two/discussion/8045/how-to-format-code-and-text

We need to use method equals() when comparing String contents: [-X
https://processing.org/reference/String_equals_.html

Polarbaer

Hi GoToLoop,

Sorry about the formatting and I appreciate your response. I've changed the code but the dot colors still won't change according to the string in the table.

It now looks like

color dot;

void draw()
{
  background(255);

  int numRows = dataTable.getRowCount();

  for (int row=0; row<numRows; row++)
  {
    float X = dataTable.getFloat(row, "X");
    float Y   = dataTable.getFloat(row, "Y");

    float xPos        = map(discIncome, 0, 2000, 0, width);
    float yPos        = map(consumed, 0, 2000, height, 0);

    String colorData = dataTable.getString(row,"educ");
    String str1 = "Type A";

    if (str1.equals(colorData) == true) 
    {
      color dot = color(255,0,0);
    }
    else
    {
      color dot = color(0,255,0);
    }

      fill(dot);
      ellipse(xPos, yPos, 5, 5);
  }
}

GoToLoop

Ru sure that both "educ" & "Type A" are correct character by character?
Whether there are any whitespaces before &/or after? :-?

Here's a more simplified example which relies on TableRow view of the original Table instance.
Pay close attention whether the acquired values x, y & type are fully correct: :-B

// forum.processing.org/two/discussion/9759/
// color-an-object-based-on-strings-in-a-table

for (TableRow tr : dataTable.rows()) {
  float x = tr.getFloat("X"), y = tr.getFloat("Y");
  String type = tr.getString("educ");

  fill("Type A".equals(type)? #FF0000 : #00FF00);
  ellipse(x, y, 5, 5);

  println("X:", x, "Y:", y, "Type:", type);
}

PhiLho

if (str1.equals(colorData) == true)
{
  color dot = color(255,0,0);
}
else
{
  color dot = color(0,255,0);
}

is wrong, because you declare a dot variable in each part of this comparison, each shadowing the global dot variable.

Remove the global variable, which has no use, and declare dot outside of the condition:

color dot = color(0,255,0);
if (str1.equals(colorData) == true)
{
  dot = color(255,0,0);
}