dd File List Select Overview

1 dd Files Generation

There are 18 different dd file types of six orientations. The orientations are View, Channel, RTS, CAL, Elements, and Header.

Channel oriented means and standard deviation type dd files are the only type that can be created from scan data files in the Scan Analysis application.

2 dd Math Functions

dd math consists of the following functions:

• Add

• Subtract

• Multiply

• Divide

• Channel to Channel difference

• Ratio of means vs. standard deviation

3 Add, Subtract, Multiply, Divide

Applies add, subtract, multiply, and divide between vectors in two dd files. The output file is a dd file with one of the following suffixes:

• .add

• .dif

• .mul

• .rat

Operations can be performed on dd files in View orientation, Channel orientation, RTS orientation, and Cal orientation.

Currently, no dd type restrictions are applied to operations between dd files, as long as the dd vectors have the same number of elements. If one file has a single vector and the other file has multiple vectors, the mathematical operation is applied multiple times using the single vector. Otherwise, the mathematical operation is applied component-wise for the number of vectors in each file.

4 Channel to Channel Difference

Applies the following calculation to the data from the data set(s) in the dd files for View, RTS or Cal orientation:

(X2-X1), (X3-X2), (X4-X3),...,(Xn-Xn-1)

where X is the data value for each channel.

The output is channel to channel dd file with extension: .c2c

5 Ratio of Means vs. Standard Deviation

Takes a MSD (means and standard deviation) or RTS (real time statistics) type of dd file, calculates the ratio of data in the means vector (1st set) to data in standard deviation vector (2nd set). The output file is a ratio type of dd file with the extension: .rat

6 dd Math Output Mode

Three output modes are supported in dd math:

• Plot - Will plot the output dd vector using an on-screen vector display.

• dd File - Allows the user to specify the output dd file name with a full path or the file basename. If only base name is provided, the program will use the default prefix and suffix for the output file. The created dd file appears in the dd file list.

• View Numbers - View Numbers will display the dd vector numerical values on the screen, and the user can perform numerical searches in the window.

7 dd Analysis User Interfaces

The dd math operation panel and a set of the dd math operation buttons are part of the ddLS screen.

8 Functions in ddLS User Interface

The ddLS supports the following functions for various file types.

• Update

• Plot

• Save to MOD

• Restore From MOD

• dd math operations: +, -, x, /, ch2ch, Ratio

• Sort By Date or Sort by Type

The user can perform these functions, except dd math operations, by simply selecting one or more files in the list select window, and clicking the function button. The following file types are supported in the ddLS user interface.

• dd File

• Cal File

• Data File

9 File Operations

• dd Math Operations - Perform: add, subtract, multiply, divide, and channel to channel difference operations on dd files. These operations are only available for dd file types.

• Plot - Plots the vector(s) of the selected files in the display window for the following file types: dd Files and Cal Files

• View # - Prints the numerical data of the dd vector(s) to the display window(s). For image file types and scan file types, it displays the VVC plots of the selected files.

• Save/Restore to/from MOD - Saves the selected files to the MOD and restores all the dd files from /MOD/ddfiles to /data directory.

• Update - Refreshes the display in the ddLS user interface.

10 dd Math Operations in ddLS

The dd math operation buttons become insensitive if no files are selected in the dd math operation panel.

The user may start dd math operation(s) by selecting the file(s) and putting them into the selection field by clicking the button FILE #1 or FILE #2. If the selected file is not a dd file, the application will not put it into the dd math operation field. A message window will pop up and ask user to select a dd file.

If only one file is selected and it is of the file type RTS dd file or MSD dd file, both CHANNEL TO CHANNEL and RATIO OF MEANS VS. STDV will become sensitive. If the selected file is not of the type MSD or RTS, only CHANNEL TO CHANNEL becomes sensitive. When two dd files are selected, ADD, SUBTRACT, MULTIPLY, and DIVIDE become sensitive and CHANNEL TO CHANNEL and RATIO OF MEANS VS. STDV become insensitive.

The user can specify the output file name when the dd file output mode is set. Otherwise the system offers a default dd file name.

The default output scaling factor is 1.0. The user can set the scaling factor to any real number.

When the dd math operation buttons are sensitive, the user can select the desired button to start the dd math operation.