I am trying to plot the distribution of scores of a continuous variable for 4 groups on one plot, and have found the best visualization for what I am looking for is using sg plot with the density fx (rather than bulky overlapping historgrams which don't display the data well). However, I'm not 100% positive on the interpretation of the x and y axes.
For the x axis, even when I set min and max values in my code, the graph displays from -50 to 200 (even though the variable's score range is 0 to 200- ie no-one has scores <0 and this doesn't make sense) - is this like a standard deviation unit below the mean? If so, do I need to set the mean for my groups? (And how would I do that?)
For the y axis, I believe this is the the theoretical proportion of all observations that would fall under the curve, at that value or less, but I just want to make sure I'm interpretting correctly.
Originally, I'd just wanted distribution curves that would be the smoothed curve version of a histogram (ie, the percent on the y axis and the true actual score, ranging from 0 to 200, on the x, but I'm not sure there's a way to do this....)
Help very much appreciated.
For the x axis, even when I set min and max values in my code, the graph displays from -50 to 200 (even though the variable's score range is 0 to 200- ie no-one has scores <0 and this doesn't make sense) - is this like a standard deviation unit below the mean? If so, do I need to set the mean for my groups? (And how would I do that?)
For the y axis, I believe this is the the theoretical proportion of all observations that would fall under the curve, at that value or less, but I just want to make sure I'm interpretting correctly.
Originally, I'd just wanted distribution curves that would be the smoothed curve version of a histogram (ie, the percent on the y axis and the true actual score, ranging from 0 to 200, on the x, but I'm not sure there's a way to do this....)
Help very much appreciated.