DC2DInvRes - DC 2D Inversion and Resolution
--release notes--

version 2.12.0 (09.09.07)
* introduced preview button into inversion options
* fixed bug in time lapse inversion with noncoinciding data
* export ascii model with topography
* introduced vtk export into model menu
* fixed bugs in reading and displaying data
* solved numerical error arising (very rarely) in sensitivity integration
* included more error catches after reading file
* unit also appears in export model
* fixed error with reading in ves/s2d files
* improved speed of 1D forward calculation
* removed bug with useless 1D forward calculation before
version 2.11.8 (07.09.07)
* identical to 2.11.7 just with full installer (no libraries necessary anymore)
version 2.11.7 (07.02.07)
* removed problems with reading borehole file
* fixed a memory bug for big data files
* solved bad representation of fix/compound/decoupling markers with topography
* fixed bug reading res2dinv files with resistances (general array)
* enhanced error estimation (Set/Add error)
version 2.11.6 (08.01.07)
* minor bug fixing and beautifying
* Set/Add button in error estimation
* fixed bug for wrong sing with infinite A electrode
* enabled reading of tx0 files from Lippmann multielectrode device
version 2.11.5 (09.12.06)
* now export graphics has again same size as in figure
* all date file types are shown for Add Data
* improved reading of flw files
version 2.11.4 (06.12.06)
* enabled infinite electrodes in AMP file
* reading in FLW files from geotom device
* manual choosing of cluster number (with default optimized value)
version 2.11.3 (27.11.06)
* improved reading stg (Sting) device files
* switched to another (fuzzy) cluster analysis showing the individual results
* ip is now part of the cluster Analysis (Model->Blockify)
* if present, phases are exported in .mod file (but not imported so far)
* export ohm option now keeps ip values
version 2.11.2 (15.11.06)
* introduced reading seismic line from file as structural information
* enabled "as measured" and "reverse" mode in forward options
  (saves calculation time for data sets with few current or potential electrodes)
* fixed hang-up with linear spacing in model parameter
* hotfix of possible hang-ups or bad axis labels
version 2.11.1 (06.11.06)
* added pdf export for File->Export Figure (thanks to epstopdf)
* improved roll-along inversion slightly
* new (faster and memory conserving) method for importing res2dinv files
* code optimization and bug fixing
version 2.11.0 (19.10.06)
* roll along inversion for very long profiles introduced (Inversion->RAI)
* enables sparse sensitivity storage (Options->Inversion: sparsify)
  saves memory for long profiles, values of 1e-5 to 1e-4 recommended
  goes not along with full resolution analysis, but single works
* slight improvement for reading soundings (s2d) files
* changed model building for underwater topography
version 2.10.4 (21.08.06)
* solved problem with loading parameters/sensitivity
* improved display of multiple gradient arrays
* minor bug fixing and beautifying
version 2.10.3 (1.8.06)
* improved soundings(s2d file) read-in and visualization
  now both resistance or app. res. can be read in (header line)
version 2.10.2 (18.07.06)
* hotfixes (data display, png export)
version 2.10.1 (14.07.06)
* reincluded command-line inversion dc2drun
* fixed bugs for hole2surface/crosshole data
* fixed bug for png export
version 2.10.0 (06.06.06)
* time lapse option now detects and inverts common configurations
* fixed wrong display of difference models (compare model and time lapse)
* corrected wrong initial options and last file remembering
* added reciprocity to Data->Edit data (if present)
* fixed loosing current/voltage when editing data
* constraints->underwater option fixes/decouples automatically
* fixed bug for subsurface electrodes in 1d cases
* data display also for subsurface electrodes
* added upper resistivity bound explicitly
version 2.9.0 (23.03.06)
* minor bux fixing and beautifying
* grid auto/on/off option in graphics options
* enabled dipole-pole configurations (fixed bug in forward calculation)
version 2.8.2 (23.02.06)
* fixed bug in reading data file (tabs, current/voltage units)
* fixed wrong rms calculation (changes nothing since chi^2 is used)
version 2.8.1 (16.01.06)
* introduced borehole layer decoupling
* introduced constraints menu including:
  boundary decoupling,resistivity fixing+compounding,reference
version 2.8.0 (02.12.05)
* fixed time lapse file bug
* recognition of reciprocity and treatment in Edit Data
* linear z-spacing and x-spacing in model parameter
* minor bug fixing and beautifying (dipole pseudosections)
* introduced smoothness decoupling (by typing X/Y into resistivity window)
* better representation of gradient configuration data
version 2.7.4a (26.10.05)
* fixed bug in exporting IP model
* fixed bug for export ohm with non-monotonic electrodes
* fixed bugs in save/load workspace
version 2.7.4 (20.10.05)
* removed bug always producing sharp boundary between 1st/2nd layer
* time lapse option to invert data differences
* showing difference model when comparing data
* removed some small bugs (2.7.3a-c)
version 2.7.3 (03.09.05)
* add error dialog when too small values
* fixed bug in reading resecs file
* enabled export of vtk files (Model menu)
* minor bug fixes
version 2.7.2 (03.08.05)
* enabled Compound regions (type C into resistivity field)
* allows Inf values in AMP files
* renamed snd-Files in s2d (to differentiate from sound and s3d files)
* introduced upper resistivity bound (input after lower bound)
* fixed bug in colorbar representation
* expanded format to unified data format (see resistivity.net)
* enabled resecs ascii output file
* fixed bug for Dipole-pole measurements
version 2.7.1 (22.06.05)
* changed release version system
* minor beautifying
* enabled reading of snd file consisting of several soundings in
  lines of: filename position flag (0=Schlumberger,1=right half,2=left half) 
* changed sensitivity plotting and fixed export
version 2.6b2 (08.06.05)
* fixed sensitivity bug (symmetry in subsurface electrodes)
* cluster analysis for post-blockifying (Shift+B)
* completely rearranged the internal system (hopefully invisible)
* fixed bug in ohm-export Tape variant
version 2.6b1 (25.05.05)
* enabled ohm-File output (useful for topo webinv)
version 2.6 (30.04.05)
* reading of ABEM multi-purpose (.amp) files
* rearranged examples directory (rename old dir)
* robust data processing and blocky model option
* fixed bug creating data (not existing field topo)
* fixed bug in model apparency
* fixed bug forgetting error estimation
version 2.5b1 (07.11.04)
* introduced license file check
* enabled topography (at this stage only weak transformation)
* fixed model opacity bug
* changed model representation
version 2.4b2 (31.10.04)
* introduced error reweighting for robust data processing
* removed some warning messages
* introduced ip in data create and model edit
* introduced enlargment and shift values for enlarged dipoles (Create Data)
version 2.4b1 (18.10.04)
* minor changes
* enabled resistivity fixing 
* enabled ip data in res2dinv export file
* inserted compare IP data
version 2.4 (31.8.04)
* changed data representation (space-less patches for "full" data)
* minor GUI beautifying
* fixed bug for small electrode distance data files
version 2.3b2 (18.05.04)
* created test version
* introduced blockify model
version 2.3
* changed name to DC2DInvRes
* changed behavior of resolution buttons
version 2.2b1 (29.04.04)
* changed model edit (now easier with with raggedbox)
* minor bug fixes
version 2.2 (23.04.04)
* enabled computation of model cell resolutions without svd
* improved CGLSPAR convergence and its waitbar
* fixed bugs and visibility
version 2.1b (20.04.04)
* improved accuracy of forward calculation
* enabled read-in of raw data files
version 2.1 (30.03.04)
* fixed export problems
* changed menu slightly
* introduced "line search" and "global regularization" inverse options
* fixed data representation error
* introduced reading in of errors in res2dinv files
version 2.0b4 (18.03.04)
* introduced misfit into Edit Data (for robust processing)
* minor bug fixes
version 2.0b3 (23.02.04)
* minor bug fixes
* introduced three boundary condition variants in GUI
  (Dirichlet, Neumann, modified Neumann)
* changed smoothness constraints 2nd order
version 2.0b2 (12.01.04)
* install program setup-inv2d.exe
* new documentation available
* fixed a lot of bugs (esp. newly introduces)
version 2.0b1 (07.01.04)
* (re-)introduced truncated least squares
* enabled choosing for TSVD and TLS
* added new figure file (buggy in 2.0b)
* enabled fewer measurements than prposed in inv2d-file
version 2.0b (05.01.04)
* changed menu structure (File,Data,Model,...)
* using measured current for error estimate
* taking current/voltage as mA/mV if values>10 occur
* bug in add data removed
* standard z layers slightly changed
version 1.6b5(15.12.03)
* included ip/chargeability inversion and display (if present)
* fixed bug in smoothness constraints (2nd order)
* included current and voltage in data files
* estimation of geometrical errors (varying electrode positions)
version 1.6b4(20.11.03)
* displaying circulating data right
* read/write data including current and voltage (if present)
* displaying number AND positions in data dialog
* included import function for 4channel-files
* 2 digits for compare model
* corrected resolution computation (also for SIRT)
version 1.6b3(27.10.03)
* introduced model compare function
* rounding electrodes for res2dinv import
version 1.6b2(15.10.03)
* removed some bugs with subsurface electrodes
version 1.6b(13.10.2003)
* increased flexibility for surface2hole and crosshole data
* improved forward calculation (esp. for subsurface electrodes)
* Edit Data also for k-factor possible

version 1.5b5(09.10.2003)
* beautifying (icons, window names, ...)
* fixed minor bugs
* expanded help menu (help, online help and web inversion)
version 1.5b4(06.10.2003)
* fixed range constraint hang-up
* fixed "matrix exeeds dimension error" in exportfigure
* printing model also prints compare window (if open)
* also encapsulated postscript(*.eps) possible for printing
* fixed error while saving sensitivity file
version 1.5b3(18.09.2003)
* changed behaviour of inversion options (manual,L-curve,fixed regu)
* introduced (test-wise) trusted region line search for one step inversion
version 1.5b2(17.09.2003)
* fixed bug in Edit data (electrodes are removed, if not used)
* changed data representation (pole-dipole, wenner, fontsize=8)
version 1.5b(11.09.2003)
* explicit definition of reference (or a-priori) model
* added "go back to old model" for one steps
* added help buttons for all option dialoges
* added option combine+delete in parameter reduction
* added option for lower resistivity bound (logarithmic parameters)
* fixed problem with non-logarithmic parameter inversion

%%%%%%%%%%%%%%%%%%%%%%%
version 1.4b3(09.09.03)
* taking parameterization from sensitivity file (if present)
* changed datum point representation
* errors in data file possible as percent
* new forward option prolonging background/boundary
* new option zmax for logspaces layer creation
* included resistivity level in create data set (important for error estimate!)
* fixed bug in forward calculation (zrefine>1, layered background)
version 1.4b2(04.09.03)
* changed sign of data misfit (data-response is more intuitive)
* changed (again) definition of chi^2
version 1.4b1(03.09.03)
* changed interpretation (and display) of chi^2
* changed (write data) formats (2 digits for all, nicifying spaces)
* Added help menu button to display online help
* beautifying and display bugs

version 1.4 (15.08.03)
*changed little, checked much
version 1.3b7 (07.08.03)
* changed ascii import/export
  (either midpoint or corner points)
* disabled alpha mapping if few resistivities present(modelling)
version 1.3b6 (31.7.03)
* fixed minor bugs
* If "Compare Data" window stays open it gets updated
* Changed menu (edit data now under main menu File)
* Changed Hotkey (O for Open data file, R reserved for (display)response
* included error estimate in Create Data Set
Version 1.3b5 (29.7.03)
* hourglass mouse pointer when busy
* area clicking of model with control(start) and shift(end)
Version 1.3b4 (21.7.03)
* Option Edit Data (under model) inserted
* maximum auto number of layers set to 12
Version 1.3b3
* (Graphics Options) Apply-bug fixed
* Bug for deleting data fixed
Version 1.3b2
* enhanced 2nd order smoothness constraints
* Creation and display of borehole-surface and cross-borehole
Version 1.3b
* Better display of mixed data sets
* Restructured menu
* Data set creation GUI
* Hotkeys only with Shift+Character
* Model importing
* Filter factors and transform function

%%%%%%%%%%%(3.2.03)
Version 1.2
* Completely arbitrary datasets
* Import of Loke/Barker files
* Graphical Edit and Save/Import of datasets
* Error estimation 
* Model Creation based on dataset 
* Interactive model edit
* Estimation of 1D starting model
* Fast and accurate forward calculation with FD
* Fast sensitivity calculation
* Many options for inversion
  (smoothness, parameter reduction, ...)
* Automatic choosing of regularization parameter
* Display of sensitivities, DOI-index, ...
* SVD resolution analysis
  (data efficiency, model resolution, ...)

Version 1.2b (20.01.03)
* Adding Error Estimate GUI (percent plus umin/I*k)
* Options for parameter limitation(combine, delete, nothing)
* Options for Weighting matrix (1, Cov, Smoothness)
* Output of CHI^2 in addition to RMS
* Transport to matlab 6.5 complete

%%%%%%%%%%%%%%%%%%%%%%
Version 1.1 (20.12.02)
* Resolution matrices basing on regularization
* Broyden update for layered (starting) model
* Graphics Export as PNG file instead of JPG
* borehole electrodes
* negative separations possible
* forward calculation faster and more accurate
* interactive modelling
* reduction of parameter possible
* fast sensitivity integration by mex function

%%%%%%%%%%%%%%%%%%
Version 1.1b (20.08.02)
* Name of file in GUI title
* x/m within XTickLabel
* number instead configuration factor
* general export function
* optional filled contour lines
* Model export as ASCII
* waitbars for all time consuming operations
* overwrite protection for all export data
* interactive deleting of measured data
* included general electrode positioning readin(type 11)
* save/load workspace
* save/load options
* saving sensitivities with x and z and checking when loading
* comments in datafile
* commas instead of blanks in data files possible
* slider for displaying sensitivities and model cell resolution

Version 1.0 (10.04.02)
* basic 2d dc inversion