It's not that a by group has one value. This only happens when there are only missing values for that group. You can work around this by telling JMP to only process groups with at least one non missing value. Here's an example I tested on a table I made with three groups (a, b, c) where group a has 3 non missing Y values, b has one missing Y value, and c has 4 non missing Y values. The grouping column is Group and the data column is Y.
style="font-size: 10pt; font-family: "Courier New"; color: black;">dt
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">Current
Data Table
style="font-size: 10pt; font-family: "Courier New"; color: black;">()
style="font-size: 10pt; font-family: "Courier New"; color: navy;">;
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
style="font-size: 10pt; font-family: "Courier New"; color: green;">//Make
list of group values for
Y;
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">Summarize
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
grp
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
by(
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Group
)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
cntgrp
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">Count
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Y
)
)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">;
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
style="font-size: 10pt; font-family: "Courier New"; color: green;">//Make
a list of groups with zero
non missing elements;
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">zerolistgrp
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
{}
style="font-size: 10pt; font-family: "Courier New"; color: navy;">;
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">For
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
i
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: teal;">1
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
i
style="font-size: 10pt; font-family: "Courier New"; color: navy;"><=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">N
Items
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;"> grp
)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
i
style="font-size: 10pt; font-family: "Courier New"; color: navy;">++,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">If
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
cntgrp[i]
style="font-size: 10pt; font-family: "Courier New"; color: navy;">==
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: teal;">0
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">Insert
Into
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
zerolistgrp
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
grp[i]
)
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
)
style="font-size: 10pt; font-family: "Courier New"; color: black;">)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">;
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: green;">//Show(
grp, cntgrp, zerolistgrp
);
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
style="font-size: 10pt; font-family: "Courier New"; color: black;">Distribution(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
Continuous Distribution(
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">Column
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Y
)
)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
By(
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Group
)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">
Where(
style="font-size: 10pt; font-family: "Courier New"; color: navy;">!
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">Contains
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">
zerolistgrp
style="font-size: 10pt; font-family: "Courier New"; color: navy;">,
style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Group
style=""> )
)
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">)
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: navy;">;