EDIT DATA

The Edit Data menu item displays a new datasheet icon on your workmap, along with a datasheet of your data. The datasheet is ready for you to edit your data. 

The menu item also turns off the menu items and many other functions so that you can safely edit your data without concern about what the rest of the system will do with a partially edited set of data.

If you wish to analyze the data as you have edited them, then you can
- right-click the datasheet and choose the CREATE DATAOBJECT item
- click on the workmap and then right-click on the datasheet icon, choosing the CREATE DATAOBJECT  menu item.

If you wish to return to the data prior to editing, simply click on the data icon to which it is attached. The data in that icon have not been altered. 

The editing you have done is not lost when you close the datasheet. 

During a single session with ViSta you can return to your editing of a datasheet at any time. You can always open it again during the same session and continue from where you left off. 

Note, however, that if your changes are not saved with the SAVE DATA AS item before you end the session with ViSta, that your changes are lost.


EDITING YOUR DATA WITH THE DATASHEET EDITOR

Datasheets display your data and let you edit your data. Datasheets can be used to create a brand new data object, to change the data in an already existing data object, or to add new data to an already existing data object. 

Datasheets support the standard editing functions.  Click on a cell to edit it.  Type the desired information.  Use the delete key to delete what you have typed. Use the cursor keys or the return, home, end or tab keys to move to another cell. 

Datasheets are not spreadsheets: They do not let you enter mathematical formulas in the cells. To do this, use a spreadsheet such as Excel. When you have the desired spreadsheet you can transfer it to ViSta as a datasheet, taking advantage of ViSta's advanced and extensive vizualization and analysis features. When you make the transfer from Excel to ViSta, Excel's numerical and textual information is transferred as is, as are the values resulting from the Excel's formulas. The formulas themselves are not transferred. 


CONTENTS OF THE DATASHEET:
The datasheet contains OBSERVATION LABELS, VARIABLE NAMES, VARIABLE TYPES and DATA, as follows:
  OBSERVATION LABELS: The left column of cells contains observation labels. These may contain any information that you wish. It is recommended that each label be unique.
  VARIABLE NAMES: The top row of cells contains variable names.  These may contain any information that you wish. It is recommended that each variable name be unique.
  VARIABLE TYPES: The second row of cells contains variable types. ViSta recognizes two variable types: Numeric and Category. Type N for numeric, C for Category. Any other information typed in these cells is ignored.
  DATA: The remaining cells of the datasheet contain the data. What you can type depends on the variable type specified for the variable (in the second header row).
  CATEGORY variables form strings from the characters typed in a cell of the datasheet. Most characters are acceptable, although some are ignored and some are interpreted as movement characters.
  NUMERIC and ORDINAL variables assume that their cells contain numbers.  For this reason you can only enter the ten digits and the characters + - . and , (the . and , can only be typed at "appropriate" places, where, I regret to say, "appropriate" is according to American rules of numeric notation).  
  SCIENTIFIC NOTATION may be used, with the scientific-notation precision-type character (d, l, f, or s) being typed at the "appropriate" place. While you can type d (double-float) l (long-float) f (single-float) or s (short-float), ViSta only uses double-float and long-float, with the conversion details depending on the machine you are using. You can determine the precision by typing the global variable MACHINE-EPSILON. The value of this variable is the smallest floating point number for which (1 + MACHINE-EPSILON) is not equal to 1.
  MISSING VALUES. The datasheet can contain missing values.  Missing values are entered as --- (three minus signs typed without spaces between them) and are displayed in the datasheet as --- or as NIL. For numeric variables --- has the numeric value equal to MACHINE-EPSILON. For character variables is is equal to NIL.


REFORMATING THE DATASHEET:
You expand the datasheet (add rows, columns or matrices) by clicking on special cells in the datasheet. To add a new observation (row) to multivariate data, click on the "New Obs" cell located below the left-hand column. To add a new variable (column) to the data, click on the "New Var" cell located to the right of the top row. You expand matrix data in a similar fashion. You can also use the EXPAND button (or menu item) to add several rows or columns simultaneously. You can control the width of columns and the number of decimal places shown by using the FORMAT button on the button bar,or appropriate items of the DESKTOP menu.


SAVING THE DATA:
You may use the button bar's SAVE button,or the FILE menu's SAVE DATA menu item to save the data. When you save the data, the current data object will be updated, unless it is attached to another icon. If so, the old data object will be left unchanged, and a new one will be created from the information in the datasheet.
