Data Analysis

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Data Analysis Graphing
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Suppose I gave you a table of data
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A long, long table
How does one make sense of all this data?
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Surface temperature (last Sunday)
The figure is capable of revealing patterns that
are not obvious in the data!
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Dependence on Time (last Sunday)
noon
400 pm
900 am
500 am
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Its evident that

• Figures can
• Re-tell the data
• Reveal patterns
• tell a story

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Multi-dimensional imaging
Consider an enormous data table containing
frequencies and the variables x, y, t, and T.
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Wind velocity whats missing?
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Velocity is a vector
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Many types of graphs
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Data summing to 100...
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Where do WIE students live?
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Where do commuter students live (2006)?
Residential
Commuter
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Graphing requirements

• Axis labels
• Unit designations
• Title
• Legend
• Caption
• A story

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Scaling telling a BAD story
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Graphs in Labs

• How did you present your data in the college
  rankings lab?
• How did you present your data in the materials
  lab?
• Why?

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When is a table better than a figure?
Five significant digits
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Whats the density of a 7 mixture?
The table shows that the density is 0.98347 g/cm3
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Data Analysis Linear Interpolation
What is the density of a 5.5 ethyl alcohol
solution at 25 C?
Determine by linear interpolation!
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Data Analysis Linear Interpolation
To solve, assume a linear relationship between

• Density and temperature and/or

• Density and ethyl alcohol

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Data Analysis Bilinear Interpolation
What if there is a non-linear relationship
between x and y?
y
x
Over small ?x, can still approximate a linear
relationship between x and y.
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Data Analysis Bilinear Interpolation
To solve, assume a linear relationship between

• Density and temperature and

• Density and ethyl alcohol

5.5, T23C

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Practice Problem then break