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NIFTI1_INTENT_CODES
NIFTI1_DATATYPES » NIFTI1_DATATYPE_ALIASES

nifti1 intent codes, to describe intended meaning of dataset contents More...

Collaboration diagram for NIFTI1_INTENT_CODES:

## Topics

| NIFTI1_XFORM_CODES
| nifti1 xform codes to describe the "standard" coordinate system

## Macros

#define | NIFTI_INTENT_CORREL 2
#define | NIFTI_INTENT_TTEST 3
#define | NIFTI_INTENT_FTEST 4
#define | NIFTI_INTENT_ZSCORE 5
#define | NIFTI_INTENT_CHISQ 6
#define | NIFTI_INTENT_BETA 7
#define | NIFTI_INTENT_BINOM 8
#define | NIFTI_INTENT_GAMMA 9
#define | NIFTI_INTENT_POISSON 10
#define | NIFTI_INTENT_NORMAL 11
#define | NIFTI_INTENT_FTEST_NONC 12
#define | NIFTI_INTENT_CHISQ_NONC 13
#define | NIFTI_INTENT_LOGISTIC 14
#define | NIFTI_INTENT_LAPLACE 15
#define | NIFTI_INTENT_UNIFORM 16
#define | NIFTI_INTENT_TTEST_NONC 17
#define | NIFTI_INTENT_WEIBULL 18
#define | NIFTI_INTENT_CHI 19
#define | NIFTI_INTENT_INVGAUSS 20
#define | NIFTI_INTENT_EXTVAL 21
#define | NIFTI_INTENT_PVAL 22
#define | NIFTI_INTENT_LOGPVAL 23
#define | NIFTI_INTENT_LOG10PVAL 24
#define | NIFTI_FIRST_STATCODE 2
#define | NIFTI_LAST_STATCODE 24
#define | NIFTI_INTENT_ESTIMATE 1001
#define | NIFTI_INTENT_LABEL 1002
#define | NIFTI_INTENT_NEURONAME 1003
#define | NIFTI_INTENT_GENMATRIX 1004
#define | NIFTI_INTENT_SYMMATRIX 1005
#define | NIFTI_INTENT_DISPVECT 1006 /* specifically for displacements */
#define | NIFTI_INTENT_VECTOR 1007 /* for any other type of vector */
#define | NIFTI_INTENT_POINTSET 1008
#define | NIFTI_INTENT_TRIANGLE 1009
#define | NIFTI_INTENT_QUATERNION 1010
#define | NIFTI_INTENT_DIMLESS 1011
#define | NIFTI_INTENT_TIME_SERIES 2001
#define | NIFTI_INTENT_NODE_INDEX 2002
#define | NIFTI_INTENT_RGB_VECTOR 2003
#define | NIFTI_INTENT_RGBA_VECTOR 2004
#define | NIFTI_INTENT_SHAPE 2005
#define | NIFTI_INTENT_FSL_FNIRT_DISPLACEMENT_FIELD 2006
#define | NIFTI_INTENT_FSL_CUBIC_SPLINE_COEFFICIENTS 2007
#define | NIFTI_INTENT_FSL_DCT_COEFFICIENTS 2008
#define | NIFTI_INTENT_FSL_QUADRATIC_SPLINE_COEFFICIENTS 2009
#define | NIFTI_INTENT_FSL_TOPUP_CUBIC_SPLINE_COEFFICIENTS 2016
#define | NIFTI_INTENT_FSL_TOPUP_QUADRATIC_SPLINE_COEFFICIENTS 2017
#define | NIFTI_INTENT_FSL_TOPUP_FIELD 2018

## Detailed Description

nifti1 intent codes, to describe intended meaning of dataset contents

[C2, chap 32] Correlation coefficient R (1 param): p1 = degrees of freedom R/sqrt(1-R*R) is t-distributed with p1 DOF.

## Macro Definition Documentation

## NIFTI_FIRST_STATCODE

#define NIFTI_FIRST_STATCODE 2

Smallest intent_code that indicates a statistic.

## NIFTI_INTENT_BETA

#define NIFTI_INTENT_BETA 7

[C2, chap 25] Beta distribution (2 params): p1=a, p2=b. Density(x) proportional to x^(a-1) * (1-x)^(b-1).

## NIFTI_INTENT_BINOM

#define NIFTI_INTENT_BINOM 8

[U, chap 3] Binomial distribution (2 params): p1 = number of trials, p2 = probability per trial. Prob(x) = (p1 choose x) * p2^x * (1-p2)^(p1-x), for x=0,1,...,p1.

## NIFTI_INTENT_CHI

#define NIFTI_INTENT_CHI 19

[C1, chap 18] Chi distribution (1 param): p1 = DOF. Density(x) proportional to x^(p1-1) * exp(-x^2/2) for x > 0. p1 = 1 = 'half normal' distribution p1 = 2 = Rayleigh distribution p1 = 3 = Maxwell-Boltzmann distribution.

## NIFTI_INTENT_CHISQ

#define NIFTI_INTENT_CHISQ 6

[C1, chap 18] Chi-squared (1 param): p1 = DOF. Density(x) proportional to exp(-x/2) * x^(p1/2-1).

## NIFTI_INTENT_CHISQ_NONC

#define NIFTI_INTENT_CHISQ_NONC 13

[C2, chap 29] Noncentral chi-squared statistic (2 params): p1 = DOF, p2 = noncentrality parameter.

## NIFTI_INTENT_DIMLESS

#define NIFTI_INTENT_DIMLESS 1011

Dimensionless value - no params - although, as in _ESTIMATE the name of the parameter may be stored in intent_name.

## NIFTI_INTENT_DISPVECT

#define NIFTI_INTENT_DISPVECT 1006 /* specifically for displacements */

To signify that the vector value at each voxel is to be taken as a displacement field or vector:

- dataset must have a 5th dimension
- intent_code must be NIFTI_INTENT_DISPVECT
- dim[5] must be the dimensionality of the displacment vector (e.g., 3 for spatial displacement, 2 for in-plane)

## NIFTI_INTENT_ESTIMATE

#define NIFTI_INTENT_ESTIMATE 1001

To signify that the value at each voxel is an estimate of some parameter, set intent_code = NIFTI_INTENT_ESTIMATE. The name of the parameter may be stored in intent_name.

## NIFTI_INTENT_EXTVAL

#define NIFTI_INTENT_EXTVAL 21

[C2, chap 22] Extreme value type I (2 params): p1 = location, p2 = scale cdf(x) = exp(-exp(-(x-p1)/p2)).

## NIFTI_INTENT_FSL_FNIRT_DISPLACEMENT_FIELD

#define NIFTI_INTENT_FSL_FNIRT_DISPLACEMENT_FIELD 2006

The following intent codes have been used by FSL FNIRT for displacement/coefficient files.

These codes are included to prevent clashes in community-created extensions to NIfTI. Encoding and decoding behavior for these intents is not specified by the standard, and support is OPTIONAL for conforming implementations.

## NIFTI_INTENT_FSL_TOPUP_CUBIC_SPLINE_COEFFICIENTS

#define NIFTI_INTENT_FSL_TOPUP_CUBIC_SPLINE_COEFFICIENTS 2016

The following intent codes have been used by FSL TOPUP for displacement/coefficient files.

These codes are included to prevent clashes in community-created extensions to NIfTI. Encoding and decoding behavior for these intents is not specified by the standard, and support is OPTIONAL for conforming implementations.

## NIFTI_INTENT_FTEST

#define NIFTI_INTENT_FTEST 4

[C2, chap 27] Fisher F statistic (2 params): p1 = numerator DOF, p2 = denominator DOF.

## NIFTI_INTENT_FTEST_NONC

#define NIFTI_INTENT_FTEST_NONC 12

[C2, chap 30] Noncentral F statistic (3 params): p1 = numerator DOF, p2 = denominator DOF, p3 = numerator noncentrality parameter.

## NIFTI_INTENT_GAMMA

#define NIFTI_INTENT_GAMMA 9

[C1, chap 17] Gamma distribution (2 params): p1 = shape, p2 = scale. Density(x) proportional to x^(p1-1) * exp(-p2*x).

## NIFTI_INTENT_GENMATRIX

#define NIFTI_INTENT_GENMATRIX 1004

To store an M x N matrix at each voxel:

- dataset must have a 5th dimension (dim[0]=5 and dim[5]>1)
- intent_code must be NIFTI_INTENT_GENMATRIX
- dim[5] must be M*N
- intent_p1 must be M (in float format)
- intent_p2 must be N (ditto)
- the matrix values A[i][[j] are stored in row-order:
  - A[0][0] A[0][1] ... A[0][N-1]
  - A[1][0] A[1][1] ... A[1][N-1]
  - etc., until
  - A[M-1][0] A[M-1][1] ... A[M-1][N-1]

## NIFTI_INTENT_INVGAUSS

#define NIFTI_INTENT_INVGAUSS 20

[C1, chap 15] Inverse Gaussian (2 params): p1 = mu, p2 = lambda Density(x) proportional to exp(-p2*(x-p1)^2/(2*p1^2*x)) / x^3 for x > 0.

## NIFTI_INTENT_LABEL

#define NIFTI_INTENT_LABEL 1002

To signify that the value at each voxel is an index into some set of labels, set intent_code = NIFTI_INTENT_LABEL. The filename with the labels may stored in aux_file.

## NIFTI_INTENT_LAPLACE

#define NIFTI_INTENT_LAPLACE 15

[C2, chap 24] Laplace distribution (2 params): p1 = location, p2 = scale. Density(x) proportional to exp(-abs(x-p1)/p2).

## NIFTI_INTENT_LOG10PVAL

#define NIFTI_INTENT_LOG10PVAL 24

Data is log10(p-value) (no params). To be safe, a program should compute p = pow(10.,-abs(this_value)). The nifti_stats.c library returns this_value as positive, so that this_value = -log10(p).

## NIFTI_INTENT_LOGISTIC

#define NIFTI_INTENT_LOGISTIC 14

[C2, chap 23] Logistic distribution (2 params): p1 = location, p2 = scale. Density(x) proportional to sech^2((x-p1)/(2*p2)).

## NIFTI_INTENT_LOGPVAL

#define NIFTI_INTENT_LOGPVAL 23

Data is ln(p-value) (no params). To be safe, a program should compute p = exp(-abs(this_value)). The nifti_stats.c library returns this_value as positive, so that this_value = -log(p).

## NIFTI_INTENT_NEURONAME

#define NIFTI_INTENT_NEURONAME 1003

To signify that the value at each voxel is an index into the NeuroNames labels set, set intent_code = NIFTI_INTENT_NEURONAME.

## NIFTI_INTENT_NODE_INDEX

#define NIFTI_INTENT_NODE_INDEX 2002

To signify that the value at each location is a node index, from a complete surface dataset.

## NIFTI_INTENT_NORMAL

#define NIFTI_INTENT_NORMAL 11

[C1, chap 13] Normal distribution (2 params): p1 = mean, p2 = standard deviation.

## NIFTI_INTENT_POINTSET

#define NIFTI_INTENT_POINTSET 1008

To signify that the vector value at each voxel is really a spatial coordinate (e.g., the vertices or nodes of a surface mesh):

- dataset must have a 5th dimension
- intent_code must be NIFTI_INTENT_POINTSET
- dim[0] = 5
- dim[1] = number of points
- dim[2] = dim[3] = dim[4] = 1
- dim[5] must be the dimensionality of space (e.g., 3 => 3D space).
- intent_name may describe the object these points come from (e.g., "pial", "gray/white" , "EEG", "MEG").

## NIFTI_INTENT_POISSON

#define NIFTI_INTENT_POISSON 10

[U, chap 4] Poisson distribution (1 param): p1 = mean. Prob(x) = exp(-p1) * p1^x / x! , for x=0,1,2,....

## NIFTI_INTENT_PVAL

#define NIFTI_INTENT_PVAL 22

Data is a 'p-value' (no params).

## NIFTI_INTENT_QUATERNION

#define NIFTI_INTENT_QUATERNION 1010

To signify that the vector value at each voxel is a quaternion:

- dataset must have a 5th dimension
- intent_code must be NIFTI_INTENT_QUATERNION
- dim[0] = 5
- dim[5] = 4
- datatype should be a floating point type

## NIFTI_INTENT_RGB_VECTOR

#define NIFTI_INTENT_RGB_VECTOR 2003

To signify that the vector value at each location is an RGB triplet, of whatever type.

- dataset must have a 5th dimension
- dim[0] = 5
- dim[1] = number of nodes
- dim[2] = dim[3] = dim[4] = 1
- dim[5] = 3

## NIFTI_INTENT_RGBA_VECTOR

#define NIFTI_INTENT_RGBA_VECTOR 2004

To signify that the vector value at each location is a 4 valued RGBA vector, of whatever type.

- dataset must have a 5th dimension
- dim[0] = 5
- dim[1] = number of nodes
- dim[2] = dim[3] = dim[4] = 1
- dim[5] = 4

## NIFTI_INTENT_SHAPE

#define NIFTI_INTENT_SHAPE 2005

To signify that the value at each location is a shape value, such as the curvature.

## NIFTI_INTENT_SYMMATRIX

#define NIFTI_INTENT_SYMMATRIX 1005

To store an NxN symmetric matrix at each voxel:

- dataset must have a 5th dimension
- intent_code must be NIFTI_INTENT_SYMMATRIX
- dim[5] must be N*(N+1)/2
- intent_p1 must be N (in float format)
- the matrix values A[i][[j] are stored in row-order:
  - A[0][0]
  - A[1][0] A[1][1]
  - A[2][0] A[2][1] A[2][2]
  - etc.: row-by-row

## NIFTI_INTENT_TIME_SERIES

#define NIFTI_INTENT_TIME_SERIES 2001

To signify that the value at each location is from a time series.

## NIFTI_INTENT_TRIANGLE

#define NIFTI_INTENT_TRIANGLE 1009

To signify that the vector value at each voxel is really a triple of indexes (e.g., forming a triangle) from a pointset dataset:

- dataset must have a 5th dimension
- intent_code must be NIFTI_INTENT_TRIANGLE
- dim[0] = 5
- dim[1] = number of triangles
- dim[2] = dim[3] = dim[4] = 1
- dim[5] = 3
- datatype should be an integer type (preferably DT_INT32)
- the data values are indexes (0,1,...) into a pointset dataset.

## NIFTI_INTENT_TTEST

#define NIFTI_INTENT_TTEST 3

[C2, chap 28] Student t statistic (1 param): p1 = DOF.

## NIFTI_INTENT_TTEST_NONC

#define NIFTI_INTENT_TTEST_NONC 17

[C2, chap 31] Noncentral t statistic (2 params): p1 = DOF, p2 = noncentrality parameter.

## NIFTI_INTENT_UNIFORM

#define NIFTI_INTENT_UNIFORM 16

[C2, chap 26] Uniform distribution: p1 = lower end, p2 = upper end.

## NIFTI_INTENT_WEIBULL

#define NIFTI_INTENT_WEIBULL 18

[C1, chap 21] Weibull distribution (3 params): p1 = location, p2 = scale, p3 = power. Density(x) proportional to ((x-p1)/p2)^(p3-1) * exp(-((x-p1)/p2)^p3) for x > p1.

## NIFTI_INTENT_ZSCORE

#define NIFTI_INTENT_ZSCORE 5

[C1, chap 13] Standard normal (0 params): Density = N(0,1).

## NIFTI_LAST_STATCODE

#define NIFTI_LAST_STATCODE 24

Largest intent_code that indicates a statistic.