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IF

Used for tests in command. 2 syntaxes are available : IF test THEN ..commands on several lines { ELSIF test2 THEN ..commands } (eventually many exclusive tests ) { ELSE (default case) ..commands } ENDIF The different commands will executed conditionnally on the value of the tests. A non-zero value is considered as true. Permits to construct complex tests in command files. IF test remaining_of_the_line execute the remaining_of_the_line conditionally on the value of test. It will be executed only if test is true (non zero). The remaining of the line can span several lines by using the line continuation sign : \ This form can be used at the prompt level, as well as in call-backs, for instance in graphic buttons. It is called the one-line IF. Tests available are : for numeral : == != < > <= >= for strings : s= s! for combinations: & | ! as well as several tests functions and variables : exist() eof() $arg $c_joined, etc... IF(in the first syntaxe) ELSIF ELSE and ENDIF should appear alone on one line, eventually followed by a comment. There is no limitation for the one-line IF.
see also : CONTROLS FOR FOREACH FUNCTIONS GOTO WHILE


IFT

Perform complex inverse Fourier Transform on data
see also : FT


IFTBIS

IFTBIS { axis } Perform inverse of complex-to-real Fourier Transform on data. This command is the basic step for Hilbert transform. The Hilbert transform is the mathematical operation which transform the real part of a causal spectrum (for instance an NMR spectrum) to its imaginary part. The command sequence : IFTBIS PHASE 90 0 FTBIS realises this operation, thus permitting to regenerate the imaginary part of the signal, when it is lost for some reasons. A more usefull operation consists in transforming a real (unphasable) spectrum to a complex (phasable) spectrum. either on place (twice as less points in the real part) (1D syntax): IFTBIS FT or with a constant resolution (zerofilling once) IFTBIS CHSIZE (%*2) FT related contexts : $ITYPE_1D $ITYPE_2D $ITYPE_3D
see also : FT


INCREM

Constant used to increment lambda during MaxEnt iteration(0.1 .. 1)
see also : LAMBCONT LAMBDA MAXENT


INITINPROGRESS

INITINPROGRESS n Presets for n iterations, the progress bar, of the form : In Progress : 0%....25%....50%....75%....100% The progress bar is then updated with the INPROGRESS command.
see also : INPROGRESS PRINT


INPROGRESS

INPROGRESS i Displays the progress of the operation in the progress bar, inited with the INITINPROGRESS command.
see also : INITINPROGRESS PRINT


INT1D

A very crude 1D graphic integrator. The data is replaced by the running sum of the previous data. Better integrals will be obtain with base-line corrected spectra. The curve can then be optimized with BCORR, ADDBASE, etc...
see also : INTEG


INTANA

The intensity analysis module implements a set of simple tools dedicated to the analysis of peak intensity according to the assignment database. It is completely written in the Gifa macro language, and can be fully adapted to your needs. The module is now contained in the button "Intens-ana" of the assignment menu. Here is a simple 'recipe' on how to use this module: If you want to produce a constraint file used for structure generation: 1) Determine accurate intensities of database peaks using the 'integ', 'sumrec', 'amoeba' or 'line-fitter procedure. The command is ? 2) Determine a set of calibration peaks, which will be used to define distance estimates on the current peak of the database (Choose the calibration intensities). This set of peaks contains the calibration distances chosen for a series of peaks, for which the corresponding intensities are contained in the database. 3) Write the output constraint file, according to the set of calibration peaks. The file cab be written in XPLOR or DIANA format, and the distance estimates can be generated in the 'build_up' or 'qualitative' ways. 'Build-up' way means that a precise distance estimate is quantitatively determined from the information contained in the peak calibration set. Then, a general uncertainty can be supposed for all the distances. If you want to generate files containing intensity variation on a series of data-sets (in the case you want to perform quantitative T1, T2 or nOe analysis). 1) Copy the database to an ascii peak file (same format than those used in pkread/pkwrite commands), and save the lookup table giving the peak index in function of the database index (command: Copy db to a pk file). 2) Then read this peak file (PkRead) and integrate it using the amoeba procedure. Save the amoeba file using the same basename than the peak file. 3) Finally, perform a multiple integration of the series of data-sets according to the saved amoeba file, using the 'Multiple Integration Tool'. For each peak in the database, an intensity file is generated and you can check it by using the 'Show Inegration Curve' command.

INTEG

INTEG factor slope thres { radius } INTEG computes the volume of the peak detected by PEAK. You need to use the peak-picker PEAK before to use INTEG. INTEG uses the methods described for the PARIS method. It first evaluate the extension of the current peak, using 3 criteria : - factor : the extension stop whenever the level goes below inten/factor (where inten is the intensity of the peak) - slope : the extension stop whenever the the slope get larger than slope/point (0 means whenever it goes up) - thres the extension stop whenever the level goes below thres. In 2D, an additional parameter is the maximum extension radius for each peak, and the extensions are stored in an amoeba file. INTEG uses the baseline and noise information held in SHIFT and NOISE, which are computed automatically by EVALN related contexts : $NOISE $SHIFT $NPK1D $NPK2D $NPK3D $PK1D_A[i] $PK2D_A[i] $PK3D_A[i]
see also : INT1D mdfamb MSKCONC MSKINTEG MSKMODIF mskread mskwrite NOISE PEAK pksumrec saveamb setamb SHIFT SIGN_PEAK SUMREC ZERO_QU


INVF

INVF {Fx} Process data-sets by multiplying by -1 1 point every 2 points. Equivalent to taking the conjugated on complex data-sets, or hyperconjugated on hypercomplex data-sets. If applied on a complex FID, inverses the final spectrum obtained after Fourier transform.
see also : FT ITYPE REVERSE REVF


INVLAP

INVLAP size Realizes the inverse Laplace transform of the current data-set, considered as regularly sampling the time domain with a sampling rate SPECW. The transform is computed for 'size' data-points spanning the range DMIN-DMAX in a logarithmic manner. The inversion is performed by MaxEnt iteration. related contexts : $ITERDONE $CHI2 $DMIN $DMAX $ALGO
see also : DMAX DMIN dosy2d dosy3d INVTLAP INVTLAPCONT LAPLACE MAXENT PUT TRANSLAP


INVLAPCONT

Continue INVLAP iteration. All the parameters may be modified before CONTinuing, but the current spectrum as hold in the working buffer should not be modified. related contexts : $ITERDONE $CHI2
see also : INVLAP INVTLAPCONT ITER MAXENTCONT


INVTLAP

INVTLAP Computes the Laplace transform of the current data-set, considered as sampled at the location tabulated in the TAB buffer. Current data-set should have the same number of points than the TAB buffer. The transform is computed for 'size' data-points spanning the range DMIN-DMAX in a logarithmic manner. related contexts : $DMIN $DMAX $SI_TAB $TAB[] $ALGO
see also : DMAX DMIN dosy2d dosy3d INVTLAP LAPLACE PUT TRANSTLAP


INVTLAPCONT

Continue INVTLAP iteration. All the parameters may be modified before CONTinuing, but the current spectrum as hold in the working buffer should not be modified. related contexts : $ITERDONE $CHI2
see also : INVLAPCONT INVTLAP ITER MAXENTCONT


IRFT

Perform inverse real-to-complex Fourier Transform on data
see also : FT


ITER

Number of iterations used by all the iterative modules of GIFA : MaxEnt with MAXENT or MAXENTCONT . But also LINEFIT and AUTOPHASE related contexts : $ITER $ITERDONE
see also : MINITER


ITERMA2

ITERMA2 value internal value for BCORR 3 algorithm
see also : BCORR BCORRP?


ITYPE

ITYPE 0..7 ITYPE is a context which describes the type of data in the image buffer. For 1D if Itype is 1 then the data-set is considered as complex (with real and imaginary parts interleaved), if Itype is 0, the data-set is considered as real. For 2D data-sets, itype takes values 0 (real) 1 (complex in dim 2, real in dim 1), 2 (complex in dim1, real in dim 2) and 3 (complex in both dimensions). For 3D data-sets, itype takes values 0 (real) 1 (complex in dim 3, real in dim 1 and 2), 2 (complex in dim 2, real in dim 1 and 3), 4 (complex in dim 1 real in dim 2 and 3) and the sums for the combinations. Itype is normally handled automatically by the program. Changing the value of Itype DOES NOT CHANGE the data, only what the program believes they are. When the itype is wrong, use another command (example FT instead of RFT) or make them real (command REAL). Results of FT, IFT, RFT, IFTBIS PK->DT, SIMU, SIMUN etc... are complex. Results from IRFT, FTBIS, MODULUS, REAL (!) etc... are real. Image from Maximum Entropy Iteration are real. Linear Prediction package works only on real FIDS. To make real FID complex,use the sequence RFT IFT. When displaying complex data sets, only the real part is shown on the screen. related contexts :$ITYPE_1 $ITYPE_2D $ITYPE_3D
see also : FLIP FLOP FT MODULUS REAL


IVALUE

Constant used to set the initial value of the image (1e-3 .. 1e3) Default value is 1.0
see also : MAXENT