Stat Menu - HP -28S Quick Reference

∑DAT A variable containing a matrix or vector.
Statistics commands operate on the real nxm matrix stored in variable ∑DAT.
Statistics functions cannot operate on complex data.
See Reserved Variables.
∑PAR A variable containing a list.
It contains four parameters for statistics operations, see COL∑.
See Reserved Variables.
∑+ Appends another row-vector of m real numbers to the ∑DAT matrix.
∑+ can also append multiple length-m vectors of data elements which are
stored in a kxm matrix.
A plain number can also be appended in case m=1.
The number of data points must match the number of colums in ∑DAT.
The number of rows n is the number of "data points".
The first ∑+ operation defines the number of columns m in ∑DAT.
∑- Removes the last line n from ∑DAT and returns it in stack level 1.
In case m=1 only a real number is returned.
N∑ Return the number of data points in ∑DAT which is the number of rows of the
matrix.
CL∑ Clears all statistics data by erasing ∑DAT. ∑PAR is not erased.
After this the next ∑+ operation defines the size of a new ∑DAT matrix.
STO∑ Takes a matrix from the stack and stores it in ∑DAT. The number of columns
in the stored matrix need not match the number of columns in – the
potentially existing – ∑DAT.
RCL∑ Returns the ∑DAT matrix to the stack. This is equivalent to '∑DAT' RCL.
TOT Adds up the values in each column of ∑DAT separately and returns a size-m
vector.
MEAN Calculates the mean value of the values in each column and returns a size-m
vector.
SDEV Calculates the standard deviation of the values in each column and returns a
size-m vector.
VAR Returns the variance of the values in each column and returns a size-m
vector. VAR is the square of SDEV.
MAX∑ Finds the maximum value in each of the columns and returns a size-m vector.
MIN∑ Finds the minimum value in each of the columns and returns a size-m vector.
COL∑ Take two numbers from the stack and store them in ∑PAR:
The 1 st
the horizontal coordinate for DRW∑ and SCL∑. For SCL∑ see PLOT Menu.
The 2 nd
the vertical coordinate for DRW∑ and SCL∑.
By default the independent-variable column is column 1 and the dependent-
variable column is column 2.
CORR Returns a real correlation value between two columns of the data matrix. The
column numbers are taken from ∑PAR and can be specified using COL∑.
COV Calculates the covariance between two columns of the data matrix. The
column numbers are taken from ∑PAR and can be specified using COL∑.
LR Calculates the linear regression thru a set of x/y-points taken from two
number (from stack level 2) defines the independent variable for LR or
number (from stack level 1) defines the dependent variable for LR or
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