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A radical view on plots in analysis. Hein Stigum Presentation, data and programs at: http://folk.uio.no/heins/. Agenda. Why use graphs Common use A graphic evolution Plots in analysis. Why use graphs?. Problem example. Lunch meals per week Table of means (around 5 per week)
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A radical view on plots in analysis Hein Stigum Presentation, data and programs at: http://folk.uio.no/heins/
Agenda • Why use graphs • Common use • A graphic evolution • Plots in analysis H.S.
Problem example • Lunch meals per week • Table of means (around 5 per week) • Linear regression H.S.
Problem example 2 • Iron level • Linear regression: Males 9.4 units higher iron level • Logistic regression: Males 10.4 times more anemia H.S.
Problem example 3 • Weight on blood pressure Missing sex H.S.
Pie and bar H.S.
Density kdensity weight Boxplot graph hbox weight Density H.S.
Scatter and density plots for many types of data x-normal use x-suggested use H.S.
Continuous by 1 category Aug-14 H.S. 17
Continuous by 2 categories • Is birth weight the same for boys and girls? Scatterplot Density plot Equal means? Linear effect? Outliers? Equal variances?
Continuous by 3 categories • Is birth weight the same over parity? Scatterplot Density plot Equal means? Linear effect? Outliers? Equal variances? H.S.
Continuous by continuous • Does birth weight depend on gestational age? Scatterplot Density plot Equal means? Linear effect? Outliers? H.S.
Binary by 2 categories • Does the low birth weight depend on sex? Jitter and line
Binary by 3 categories • Does the low birth weight depend on parity?
Binary by 3 categories, no scatter • Does the low birth weight depend on parity?
Scatter: binary by countinuous • Does the low birth weight depend on gest. age? H.S.