Turbo-BrainVoyager v3.2

Volume Data Access Functions

float tGetValueOfVoxelAtTime(int x, int y, int z, int timepoint)

Provides the signal value as a 4-byte float value of the voxel specified by the coordinate parameters "x", "y" and "z" for the given time point (0-based indices). The given "timepoint" parameter must be smaller than the value obtained by the "tGetCurrentTimePoint()" function. This function should be used in the "executePostStep()" function since at this call all specified TBV preprocessing steps have been already performed such as 3D motion correction or 3D spatial smoothing. For details, see the "Export Volume Data" example plugin. To get raw signal data, use this function in the "executePreStep()" function. Note, however, that the data is only un-preprocessed for the actual time point ("tGetCurrentTimePoint() - 1") since past values will have been preprocessed at later time points; this conceptual point needs not be considered in case that no preprocessing options are enabled in the TBV settings file.

short int **tGetTimeCourseData()

Provides a direct pointer to the full time course data that is also used internally in TBV. Individual values are 2-byte short integers. The data is organized in a [time][voxel] manner, i.e. the first index addresses a volume at a specific time point while the second index addresses a voxel index; if a voxel with specific coordinates needs to be accessed, use the term "z_coord*dim_x*dim_y + y_coord*dim_x + x_coord". For details, see the provided example plugins.

double tGetBetaOfVoxel(int beta, int x, int y, int z)

Provides the value of a beta indexed by the "beta" parameter as a 8-byte double value for the voxel specified by the coordinate parameters "x", "y" and "z" (0-based indices). This function allows to access estimated beta values resulting from the incremental GLM performed by TBV. Note that the beta index ranges from 0 to the current number of predictors; to retrieve only the betas of the predictors of interest, the beta index must be smaller than "tGetCurrentNrOfPredictors()" minus "tGetNrOfConfoundPredictors()". For details, see the "Export Volume Data" example plugin.

double *tGetBetaMaps()

Provides a direct pointer to the full stack of beta maps that is also used internally in TBV. Individual entries are high-precision (double) values. The data is organized as a flat array; in order to obtain the beta value of a specific predictor index for a voxel with specific coordinates, use the term "beta_i*dim_xyz + z_coord*dim_xy + y_coord*dim_x + x_coord". Note that the beta_i index must be in the ranges from 0 to the current number of predictors; to retrieve only the betas of the predictors of interest, the beta index must be smaller than "tGetCurrentNrOfPredictors()" minus "tGetNrOfConfoundPredictors()". For details, see the provided "Export Volume Data" plugin.

float tGetMapValueOfVoxel(int map, int x, int y, int z)

Provides the value of a t map indexed by the "map" parameter as a 4-byte float value for the voxel specified by the coordinate parameters "x", "y" and "z" (0-based indices). This function allows to access calculated contrast values that are calculated based on the beta values from the incremental GLM performed by TBV. The "map" index ranges from 0 to one less than the number of contrasts specified in the TBV settings file (implicitly or via a specified contrast ".ctr" file); the number of contrasts can be retrieved using the "tGetNrOfContrasts()" function. For details, see the "Export Volume Data" example plugin.

float *tGetContrastMaps()

Provides a direct pointer to the full stack of contrast maps that is also used internally in TBV. Individual entries are 4-byte float values. The data is organized as a flat array; in order to obtain the t value of a specific contrast map index for a voxel with specific coordinates, use the term "map_i*dim_xyz + z_coord*dim_xy + y_coord*dim_x + x_coord". The "map_i" index ranges from 0 to one less than the number of contrasts specified in the TBV settings file (implicitly or via a specified contrast ".ctr" file); the number of contrasts can be retrieved using the "tGetNrOfContrasts()" function. For details, see the provided "Export Volume Data" plugin.