In Gnuplot, `stats`

can help you to do some statistical works easily. For example, correlation coefficient:

**Take a look of chapter “Stats” in gnuplot manual first.**

# Use `stats`

1 | stats data using 5:4 name "A" |

`data`

should be replaced with your data file or data variable.

Now, all statistics data have been generated automatically and ready to be used.

“A” is to be set as **prefix**.

For example, variable `A_correlation`

is the correlation coefficient value between col 5 & 4.

# Correlation Coefficient

Update: Sorry, it’s correlation coefficient, not R

^{2}.

Add a label to show correlation coefficient on the plot:

1 | set label 1 sprintf("r = %4.2f",A_correlation) at graph 0.1, graph 0.85 |

# Linear Fit

Variable | Meaning |
---|---|

`STATS_correlation` |
correlation coefficient between x and y values |

`STATS_slope` |
A corresponding to a linear fit y = Ax + B |

`STATS_intercept` |
B corresponding to a linear fit y = Ax + B |

So we can define a linear equation `y = mx + c`

to draw it:

1 | line_fit(x)=A_slope*(x)+A_intercept |