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#### 8.2.45.4 octave.dataset.anscombe

Static Method: out = anscombe ()

Anscombe’s Quartet of “Identical” Simple Linear Regressions

#### Description

Four sets of x/y pairs which have the same statistical properties, but are very different.

#### Format

The data comes in an array of 4 structs, each with fields as follows:

`x`

The X values for this pair.

`y`

The Y values for this pair.

#### Source

Tufte, Edward R. (1989). The Visual Display of Quantitative Information. 13–14. Cheshire, CT: Graphics Press.

#### References

Anscombe, Francis J. (1973). Graphs in statistical analysis. The American Statistician, 27, 17–21.

#### Examples

```data = octave.dataset.anscombe

# Pick good limits for the plots
all_x = [data.x];
all_y = [data.y];
x_limits = [min(0, min(all_x)) max(all_x)*1.2];
y_limits = [min(0, min(all_y)) max(all_y)*1.2];

# Do regression on each pair and plot the input and results
figure;
haxs = NaN (1, 4);
for i_pair = 1:4
x = data(i_pair).x;
y = data(i_pair).y;
# TODO: Port the anova and other characterizations from the R code
# TODO: Do a linear regression and plot its line
hax = subplot (2, 2, i_pair);
haxs(i_pair) = hax;
xlabel (sprintf ("x%d", i_pair));
ylabel (sprintf ("y%d", i_pair));
scatter (x, y, "r");
endfor

# Fiddle with the plot axes parameters