Excel help - WIBR BaRC

WIBR Microarray Analysis Course - 2007

Cell conventions

  1. Cells are referred to by their column letter and row number (ex: A2).
  2. A series of cells are referred to by showing the starting and ending cells, separated by a colon (ex: A2:A100).
  3. When cells are copied and pasted, the column and row are shifted to adjust to the position of the new cell. For example, if the formula "=B5" is copied and pasted one cell to the right, the formula in the new cell will change to "=C5".
  4. If you wish to maintain the position(s) of cell(s) in a formula, use the prefix "$" to create an absolute link to cells that won't change with copying an pasting. For example, if the formula "=$B$5" is copied and pasted one cell to the right, the formula in the new cell will still be "=$B$5". You may use the prefix "$" before the column and/or the row.
  5. Refer to cell(s) in another worksheet by prefixing the cells with the sheet name plus "!". Ex: "=data!B4" refers to cell B4 on a worksheet named "data". For this reason it's very helpful to name worksheets with short but informative names.
  6. Refer to cell(s) in another file by prefixing the cells with the file in square brackets and the sheet name plus "!". Ex: "=[anotherFile.xls]data!B4" refers to cell B4 of file "anotherFile.xls" on a worksheet named "data".

Copying and pasting cells

  1. Copying and pasting cells usually has the expected result. If not, check your use of "$" (to fix a location).
  2. When copying and pasting data generated by a formula, it may be best (to prevent re-calculations of data) to paste the actual value, rather than the underlying formula. To do this, copy the cell(s) as usual but then select "Paste Special > Values".

Using functions

  1. Excel contains a reasonable range of functions which can be used by in one of at least two ways:
  2. At any time, entering the function name into the help box or selecting "Help on this function" usually provides a brief explanation of the function and some examples.
  3. If you make a mistake with a function, you might get a suggestion to correct it. If you agree to the correction, check the input and output!
  4. You may find that Excel calculates functions too often to your liking (especially if it takes a while). If that happens,
    • Windows: go to Tools > Options
    • Mac: go Excel > Preferences
    and select the Calculation tab. Then select Manual under Calculation. Then Excel will only perform calculation on the file when you use F9 or on the active worksheet when you use SHIFT+F9.
  5. Some functions and a few supplementary data analyses can be accessed from "Tools > Data Analysis". If you don't see this option, you may have to install the tools. In that case, select "Tools > Add-Ins" and check Analysis ToolPak. Then try "Tools > Data Analysis" again.

Shortcut for selecting a large number of cells

  1. One can always use the scrollbars to select lots of cells, but with big spreadsheets, this isn't very efficient.
  2. To start the selection of a large matrix, start by selecting the bottom right cell of the desired matrix.
  3. Use "Control - Shift - Up arrow" to select everything above the original cell.
  4. Use "Control - Shift - Left arrow" to select everything to the left of the original cell.
  5. Use "Shift - Down arrow" to move down one row (to avoid the header line, if present).
  6. Use "Shift - Right arrow" to move to the right one column (to avoid any ID column(s), if present).
  7. Note: This should work with both Windows and Macintosh computers.

Functions for microarray analysis

  1. SUM
  5. LOG
  6. IF
  7. AND
  8. MIN
  10. TTEST
  12. RANK

WIBR Microarray Analysis Course - 2007