JMP Example 2
Say you take 5 measurements for the yield from a
granulator and find the mean measurement.
You repeat this process 50 times, to generate a
distribution of the data.
It can be shown that using 10 or 20 measurements in
the first step will give greater accuracy and less
variability.
Use the data given in MS Excel to make distributions in
JMP. Note the change in the shape of the distributions
with an increase in the individual sample size, n.
Open JMP, as
demonstrated in
the last example.
Select the “New
Data Table”.
Automatically, there is only one
column on the Data Table. We need to
add 2 more, since we have 3 sets of
data. Left click on the right-most red
arrow to toggle the column settings.
There are a series of different
functions you can carry out on
the columns. For this example,
we need to add multiple
columns.
To add columns to the
Data Table, we select the
“Add Multiple Columns…”
tab.
Here, we may add as
many columns as we
need. We need three
columns in total.
Then press OK.
Now we have the three columns; but
we need to change their titles.
Highlight all of the column title boxes.
Select the red arrow
which toggles the
column controls.
This time, we will select
the “Column Info…” tab.
Note we can change
more than just the title
here.
The “Column Settings” Window
will allow you to change things
like the width of the column and
the number of rows in the
column. Highlight the column
name to change it. Repeat for
each column.
The “Column Settings” Window
will allow you to change things
like the width of the column and
the number of rows in the
column. Highlight the column
name to change it. Repeat for
each column.
The “Column Settings” Window
will allow you to change things
like the width of the column and
the number of rows in the
column. Highlight the column
name to change it. Repeat for
each column.
The “Column Settings” Window
will allow you to change things
like the width of the column and
the number of rows in the
column. Highlight the column
name to change it. Repeat for
each column.
Then press OK.
We also need to add
the actual data from
MS Excel.
To add just one row,
double left click on
the first box in the
left-most Column.
A row will appear
across all the
columns.
This is the data set with which
you are supplied in MS Excel.
Highlight the data as shown.
Hold the control key “Ctrl” on
your keyboard, and press the
“C” key on your keyboard. This
copies the highlighted data.
When back in JMP, hold
down the “Ctrl” key as
before, and press “V”. This
will paste the data in JMP.
Note: Make sure you have
all the row highlighted
before you do this.
Otherwise it will not work.
Similarly to
Example 1, we
want to use the
“Distribution”
capability in JMP.
Since we have 3 Columns, we
have 3 different data sets upon
which we can choose to model
the distribution. Select the first
one, entitled “Yield (%) with 5
Samples,” and press the “Y,
Columns” button.
Then press OK.
The distribution of
that column will
then be drawn.
Repeat for all
columns required.
The distribution of
that column will
then be drawn.
Repeat for all
columns required.
The distribution of
that column will
then be drawn.
Repeat for all
columns required.
The distribution of
that column will
then be drawn.
Repeat for all
columns required.
The distribution of
that column will
then be drawn.
Repeat for all
columns required.
You will then have the three distributions. However, the objective is to compare each
distribution. As was shown in the previous example, alter the range and increments of
the distributions so that they are all equally weighted on the plots. You may also apply
the use of a reference line in the same window. If you need to adjust the graphs
further, use the “Grabber” on the toolbar.
Here would be a valid comparison on the three distributions. Note the Box Plot, a
common form of distribution summary, over the histograms. The longer the box
plot, the larger the variance. You might say the plot of the yield with 20 samples
tends more towards a Gaussian (or normal) distribution (a.k.a. the Central Limit
Theorem).