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>a3:"    LESSON4 -- Replicating Formulas, Inserting, Deleting & Moving
>a6:"       In Lesson2 we learned how to enter numbers, labels, and 
>a7:" formulas into the spreadsheet.  In this lesson we will examine how
>a8:" formulas are 'replicated'.  Also, we will see how lines and columns
>a9:" can be inserted, deleted, and moved.  We will be using a spreadsheet
>a10:" that analyzes 'Cash Flow' for a small business.
>a12:"      Move the cursor to line  11  and type the CREATE TWO WINDOWS
>a13:" Command:
>a14:"                        Control--x  2
>a15:"       Do not synchronize the windows.
>a16:"       Move the cursor to the top window, using the OTHER WINDOW
>a17:" Command:
>a18:"              Control--x  o  (small letter 'o')
>a19:" Again, you will need the 'Other Window' commands to scroll the lesson.
>a21:"       With the cursor in the top window type the FIND FILE Command:
>a23:"                       Control--x  Control--f
>a25:"     Type the filename 'cash.pc' followed by a carriage return.      
>a27:"       Perfect Calc displays a sample 'Cash Flow Assessment' program
>a28:" in the top window.
>a30:"       Let us begin by examining the entire spreadsheet.
>a31:"       When you have seen the entire spreadsheet, position the cursor
>a32:" at entry box 'b10', which records "Total Cash Flow In" for January.
>a33:" The formula which displays in the Prompt Line is:
>a35:"                      Formula: sum(b5:b8)
>a37:"       This formula instructs Perfect Calc to add the entries in the
>a38:" previous four entry boxes ('b5' to 'b8') and to display the result in 
>a39:" in 'b10'.
>a40:"       Move the cursor one space to the right to the entry box which
>a41:" records the same information for February.  Here the formula is:
>a42:"              Formula: sum(c5:c8)
>a43:"       Except for their variables the two formulas are identical.  Move
>a44:" the cursor across line 10, noticing that the formulas differ only in
>a45:" the coordinates that specify their individual column positions. This is
>a46:" a common way of structuring consecutive formulas--varying them slightly
>a47:" to account for their positions on the spreadsheet.  Entering a series
>a48:" of such formulas could prove tedious, were it not for a procedure which
>a49:" Perfect Calc provides called 'replicating'.  Let us see how it works.
>a51:"       Let us enter a similar formula into Line 18, which computes
>a52:" 'Total Cash Flow Out' for each month of the year.  Move the cursor to 
>a53:" position 'b18' æTo get there type Control--vå. The formula to be
>a54:" replicated will be:
>a55:"                      b18 = sum(b13:b16)
>a57:"       Like 'Total Cash Flow In', this formula will be duplicated to
>a58:" every entry box in line 18, its coordinate variables changing to
>a59:" reflect the various column positions.
>a61:" REPLICATING A FORMULA
>a63:"       With the cursor in position 'b18' type the initial formula for
>a64:" this position.  Begin with an equals sign  (  =  ):
>a65:"                  FORMULA: b18=sum(b13:b16)
>a66:"     Enter this formula with a carriage return.  Next type the
>a67:" COPY ENTRY Command:
>a68:"                           Control--W
>a69:"     Perfect Calc saves the formula in a temporary storage space called
>a70:" the 'Save Buffer' for later duplication to other locations.
>a71:"       Set an invisible mark at position 'b18' using the MARK SET
>a72:" Command:
>a73:"                       Escape. . .<space bar>
>a75:"       Perfect Calc responds:  "Mark set at b18" .
>a76:"       This 'mark' defines the beginning of the 'region' over which
>a77:" the formula will be replicated.
>a78:"       Move the cursor to the end of line 18 using the END OF LINE
>a79:" Command  (Control--E).  The new position of the cursor defines the
>a80:" other boundary of the region.
>a81:"      Replicate the formula across the region of entry boxes in line 18
>a82:" by giving the multiple YANKBACK Command:   Escape...y
>a83:"   At this point Perfect Calc needs to know only one more thing: whether
>a84:" or not the two variables in the formula are 'relative'. That is, should
>a85:" they be changed to reflect the positions of the various entry boxes to
>a86:" which the formula will be 'replicated'?  It asks this by displaying the
>a87:" formula in the Prompt Line and 'bracketing' the variable in question:
>a88:"            b18 = sum( >b13< :b16). . .Relative?
>a89:" Here, the variable 'b13' is bracketed. The answer, of course, is 'y'
>a90:" for yes.  The question is asked for 'b16'. Again the answer, 'y'.
>a92:"       Perfect Calc immediately replicates the formula to the entry 
>a93:" boxes in line 18, February to December.  At each entry the value '0'  
>a94:" is now displayed, indicating that so far no cash has been paid 'out'
>a95:" for any month.  Move the cursor backward along line 18 to see the
>a96:" replicated formulas.
>a98:"       Replicating is a simple and easy procedure that you will use 
>a99:" again and again in building your spreadsheets.
>a101:"  INSERTING
>a102:"       Inserting a line or column is also easy to do.  It is usually
>a103:" employed when making room for additional data that is either new or
>a104:" was forgotten when the spreadsheet was created.
>a106:"       For example, suppose that we wished to add a line recording
>a107:" phone expenses under 'Cash Flow Out'.  The line should be inserted
>a108:" somewhere WITHIN the range of expenses already present, perhaps
>a109:" between 'Supplies', line 15, and 'Other', line 16.  Therefore,
>a110:" position the cursor on entry box 'a16', where 'Other' is displayed.
>a111:" Type the OPEN LINE Command:
>a112:"                             Control--o  (lowercase letter 'o')
>a114:"       Perfect Calc inserts a blank line, shifting 'Other' and all
>a115:" lines below it down one line.  'Other' has become line 17, 'Total
>a116:" Cash Flow Out' line 19, etc.  All formulas contained in these
>a117:" lines have been modified to reflect their new line positions.
>a119:"       With the cursor at the beginning of the new line 16, press the 
>a120:" space bar 3 times and type the label 'Postage'.
>a121:"       It should be emphasized that the new line has been completely
>a122:" integrated into the spreadsheet.  That is, the formula in the spread-
>a123:" sheet which referenced this range of lines ('Total Cash Flow Out') has
>a124:" automatically been altered to include the new line.  Move the cursor to
>a125:" entry box 'b19'.  The original formula was:
>a126:"                                             b18 = sum(b13:b16)
>a128:"       After the new line was inserted, this became:
>a130:"                                        b19 = sum(b13:b17)
>a132:"       Perfect Calc will automatically alter formulas that compute a
>a133:" range of entries, and among which a new line has been inserted.  Of
>a134:" course, if the line is inserted outside the range, then the formula
>a135:" will have to be altered manually to take account of the insertion.
>a137:"       For example, if we had inserted 'Postage' BELOW 'Other', at line
>a138:" 17, the formula which computes 'Total Cash Flow Out', and which
>a139:" originally included only values in the range 'b13' to 'b16' would 
>a140:" have had to be manually altered to include position 'b17'.
>a142:"       Inserting a column is performed in a similar fashion to inserting
>a143:" a line except that Perfect Calc opens a new column, instead of a line,
>a144:" at the position of the cursor.  With the cursor in column 'b' type the
>a145:" OPEN COLUMN Command:
>a146:"                            Escape...o   æthe letter 'o'å
>a148:"     Perfect Calc inserts a new column 'b' moving all the other columns
>a149:" over 1.  What was in column 'b' has been moved to column 'c', what was
>a150:" in column 'c' has been moved to column 'd' and so on.
>a151:"  DELETING
>a152:"       Deleting a line or column from a spreadsheet is as easy as
>a153:" inserting a line or column.  Let us suppose that we wish to delete
>a154:" line 14, 'Utilities'.  Move the cursor to any entry position on this
>a155:" line and type the DELETE LINE Command:
>a156:"                                           Control--c
>a158:" Perfect Calc deletes the line, shifting all lines below the deletion up
>a159:" by one and renumbering them.  As when inserting a line, all formulas
>a160:" within these lines are adjusted to reflect their new positions.
>a162:"       It is possible to delete not only lines, but single entries, 
>a163:" columns, and even regions of data.  Let us delete the new column we
>a164:" inserted in column 'b'.  Move the cursor to any position in column 'b'
>a165:" and enter the DELETE COLUMN Command: 
>a167:"                        Escape...c
>a169:" Details for other delete operations are provided in your Perfect Calc
>a170:" User's Guide.
>a171:"       We should note that deleting data may at times entail some risk,
>a172:" because the chance exists that the deleted line or column is being
>a173:" referenced by some formula variable in another part of the spreadsheet.
>a174:" When this happens, the referencing formula may compute to 'Error!' at
>a175:" the next recalculation.  The formula is, in fact, left with a 'blind'
>a176:" reference to a non-existent line or column.  Other formulas which
>a177:" reference THAT formula will also begin computing to 'Error!'  There-
>a178:" fore, it is always a good habit to check carefully for formulas which
>a179:" might reference the data about to be deleted, and to alter them
>a180:" accordingly before any deletion is made.
>a181:"  YANKBACK
>a182:"   Perfect Calc temporarily saves every deletion in its 'Save Buffer', a
>a183:" reserved space in computer memory.  It is therefore possible to restore
>a184:" the most recent deletion from this buffer using the YANKBACK Command:
>a185:"               Control--y
>a186:"  For example, let us delete the 'Supplies' line by moving the cursor 
>a187:" to line 14 and entering:  Control--c.
>a188:" -- Do not make any further deletions, since these will replace the
>a189:"    'Supplies' Line being held in the 'Save Buffer'. Look at the result.
>a190:" -- Type the YANKBACK Command :   Control--y.
>a192:"       Perfect Calc immediately restores the 'Supplies' Line, shifting 
>a193:" all lines below this down by one and renumbering.
>a195:"     Deleted entries, columns, and regions of data can also be restored
>a196:" in this manner. 
>a198:"     (For more complete details see your User's Guide.)
>a201:"  MOVING DATA
>a202:"       The Procedure for 'moving' lines and columns to new locations
>a203:" is IDENTICAL to that we have just seen for restoring a deletion,
>a204:" except that the material is restored from the Save Buffer to a 
>a205:" DIFFERENT location in the spreadsheet.  To see how this works, let us
>a206:" move 'Postage' from line 15 to below 'Rent' at line 14.
>a208:" First, delete 'Postage' with the DELETE LINE Command:  Control--C.
>a209:" -Then, move the cursor to the 'Supplies' line, below 'Rent'.
>a210:" -Reinsert the line using the YANKBACK Command,  Control--Y.
>a212:" END
>a213:" This concludes Lesson4.  Be sure to save the modifications you have
>a214:" to the 'cash.pc' file, since you will be using this file in Lesson5.
>a215:" Enter:   
>a216:"         Control--x  Control--w    and supply the filename 'cash1.pc'.
>a218:" Lesson5 deals with copying data between spreadsheets.  If you want to
>a219:" proceed with Lesson5 now, then clear the computer's memory and read in
>a220:" the 'lesson5.pc' file
>a222:"       If you do not wish to continue, type the QUIT Command:
>a224:"                     Control--x  Control--c
>a226:"       Answer 'yes' to Perfect Calc's question: "Ignore changes this
>a227:" session?"
>a229:"                      END OF LESSON 4
>a1
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