AGB 260:
Agribusiness
Information
Technology
Importing Data, Managing and
Transforming Data, Data Validation,
and Handling Errors
Useful Chapters in the Textbook
Regarding this Lecture

Chapter 26

Chapter 31

Chapter 32
Valuable Sources of Data

http://aic.ucdavis.edu/research/datasources.htm

http://www.ers.usda.gov/data-products.aspx

http://www.bls.gov/

http://www.cdfa.ca.gov/statistics/

https://www.census.gov/
Importing Data

The data that you work with in
Excel can be entered in a few basic
ways.

You can enter the data by hand one
data cell at a time which can be
inefficient.
Importing Data Cont.

You can copy the data and try to
paste it into Excel.

Fortunately, Excel has the
capability to import many different
types of data.
Importing Data Cont.
 There
are several sources you
can import data from:
 Access
Database
 From
the Web
 From
Text
 From
other Sources
Copy and Paste

Sometimes you can input data into
Excel by just copying it and then
pasting it.

To do this, go to the source
document, highlight the data, copy
it, and then paste it into Excel.

Sometimes Excel is smart enough to
enter the data correctly.
Copy and Paste

Other times it will bring the data in
as a text in a single column.

Excel has the ability to turn data
that is in a single column into data
that spans multiple columns.

In class we will work with:
 http://www.cdfa.ca.gov/Statistics/PD
Fs/ResourceDirectory_2013.pdf
Importing Data Through the
Web

On the Data Ribbon under Get
External Data, there is a button
that allows you to get data from the
Web.
 When
you press this button, Excel
brings up a page that looks like a web
page.
 From
here you can enter the web page
that has the data you are interested in
importing.
Importing Data Through the
Web Cont.
 Once
you are on the web page,
you will see yellow arrows and
associated box around what Excel
can import.
 Click
on the yellow arrow to
select the data and then click on
import.
Importing Data Through the
Web Cont.

Try the import from web tool with the
following websites:
http://www.bls.gov/news.release/cpi.t01
.htm

http://finance.yahoo.com/q/hp?s=YHOO
Handling Duplicate Values
and Creating Histograms

There are times when your data set
has many duplicate values and you
are interested in the frequency of
those values known as a histogram.

Excel has the ability to remove
duplicate values on the Data
ribbon.

Once you remove these duplicates,
you can use the unique values to
develop a histogram.
Histogram In-Class Activity

In column A, copy the RandBetween(1,10)
function in cells A1:A5000.

Copy and paste special those values into
the C column.

Remove the duplicates from this new
column.

Create a histogram out of the original
data using the non-duplicate values and
the Countif() function.

Press F9 several times to see how the
histogram changes.
Data Validation

Excel has a tool that can ensure
that the data that is being entered
is the correct type of data.

This tool is the Data Validation Tool
located on the Data ribbon.

The tool has three tabs:
 Settings
 Input
Message
 Error
Alert
Data Validation Cont.

The Data Validation tool can check
to see if the data entered is a:
 Whole
number
 Decimal
 List
 Date
 Time
 Certain
text length
 Custom
(which is based on a formula)
Data Validation Cont.

With the Data Validation tool, you
can set-up a message that tells the
individual what type of data they
should enter.

The Data Validation tool allows you
to also put an error message in case
a correct value is not entered.
Data Validation Cont.
 You
have the option to:
 Stop
the individual before the
wrong data is entered,
 Provide
a warning to the individual
about the wrong data, or
 Provide
information to the
individual regarding the wrong data.
Different Types of Errors
 #DIV/0!—This
error alerts you
when you have divided by zero.
 #N/A—This
error alerts you when
the information is unavailable.
 #NAME?—This
error alerts you
Excel does not know the name
you are using, e.g., =SQRT(dog).
Different Types of Errors
Cont.

#NULL!—This error indicates that
the formula you are using does not
have an intersection point.
 Most
of the time this error occurs
because you are missing an operator,
e.g., =SUM(A3:A5 A4:B7) vs.
=SUM(A3:A5 B3:B5).

#NUM!—This error alerts you to an
invalid number, e.g., Sqrt(-100).
Different Types of Errors
Cont.

#REF!—This error alerts you to an
invalid cell reference.


This typically happens when you delete a
referenced worksheet in a formula.
#VALUE!—This error alerts you to
incorrect data types, a function’s
argument is a range when it should
be a single value, e.g.,
=SQRT(A3:A4)
Different Types of Errors
Cont.
 The
Iferror() function can
handle errors when they come
up.
 The
Iserror() function can
check to see if you have an
error; it returns true or false.
Auditing Toolbar and Formula
Auditing

Excel on its Formulas ribbon has a
section for formula auditing.

This tool allows you to trace the
precedents and dependence of a
cell.
Auditing Toolbar and Formula
Auditing Cont.

It can allow you to toggle between
the formulas and the results in a
cell.

It can show you how a formula is
being evaluated.
Circular Reference Errors

When building formulas, you
sometimes run into an error known
as a circular reference.

This error is alerting you to the fact
that the cell you are currently
calculating is somehow reliant upon
itself causing a circular reference.
Circular Reference Errors
Cont.

Sometimes you can use circular
references as a tool for making a
calculation, but typically it is an error you
need to handle by fixing the circular
reference.