# Wolfram Mathematica

## Visualize Seasonal Patterns

Compare seasonal precipitation in a Midwest and a Southwest location.

WeatherData provides aggregated precipitation in cm.

In[1]:=
```start = {1999, 1, 1}; end = {2015, 12, 31};```
In[2]:=
```getData[place_] := WeatherData[place, "TotalPrecipitation", {start, end, "Month"}]```

Create a TimeSeries of precipitation for Champaign, IL, and Phoenix, AZ. Specify MissingDataMethod to use interpolation to fill in missing data.

In[3]:=
```makeTS[place_] := TimeSeries[getData[place], MissingDataMethod -> "Interpolation"]```
In[4]:=
```tsIL = makeTS[ Entity["City", {"Champaign", "Illinois", "UnitedStates"}]]```
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In[5]:=
`tsAZ = makeTS[Entity["City", {"Phoenix", "Arizona", "UnitedStates"}]]`
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Create WeightedData with amounts of precipitation as weights and plot DateHistogram averaging the data over the total number of years.

In[6]:=
```dataIL = WeightedData[tsIL["Dates"], tsIL["Values"]]; dataAZ = WeightedData[tsAZ["Dates"], tsAZ["Values"]];```
In[7]:=
`totalyears = (end[[1]] - start[[1]] + 1);`
In[8]:=
`avg := Function[{x, y}, y/totalyears]`
In[9]:=
```makeHistogram[data_, lab_] := DateHistogram[data, "Month", avg, DateReduction -> "Year", PlotRange -> {All, {-1, 9}}, AxesLabel -> "cm", PlotLabel -> lab]```
In[10]:=
`{makeHistogram[dataIL, "IL"], makeHistogram[dataAZ, "AZ"]}`
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