vbmeg2_load_functions
vb_load_cortex
Description
Loads cortical model of standard brain.
Syntax
[V, F, xx, inf_C] = vb_load_cortex(brain_file, coord_type);
Parameters
- brain_file
- <<string>> VBMEG Cortical model file(.brain.mat).
- coord_type
- <<string>> The coordinate system of the V to be loaded.
- (not specified)
- return value Standard cortex vertices in VBMEG coordinate. [Default]
- 'Inflate'
- return value Inflated standard cortex vertices in VBMEG coordinate.
- 'MNI'
- return value Standard cortex vertices in MNI coordinate.
Returns
- V
- Cortex vertex coordinates. [Nvertex x 3]
- F
- <<structure>> Triangle patch index structure.
- .F3R
- Triangle patch index of right hemisphere. [NRfaces x 3]
- .F3L
- Triangle patch index of left hemisphere. [NLfaces x 3]
- .F3
- Triangle patch index of both hemisphere. [Nfaces x 3]
- xx
- Normal vector to cortical surface. [Nvertex x 3]
- inf_C
- Color correspoding to Gyrus in inflate data.(When 'Inflated' is specified for coord_type [Nvertex x 1]
vb_load_current
Description
Loads estimated cortical current of standard brain.
syntax
[Jinfo, J] = vb_load_current(curr_file, curr_type, ave_mode, trial);
Parameters
- curr_file
- <<string>> VBMEG Cortical current file(.curr.mat).
- curr_type
- <<integer>> loading current type.
- 0
- Cortical current excluding zero activity vertex.
- 1
- Cortical current on reduced vertex. (due to bayes_parm.reduce)
- 2
- Cortical current on all vertex. [Default]
- ave_mode
- <<integer>> average mode of loading current.
- 0
- No trial average.
- 1
- trial average is done. [Default]
- trial
- <<vector>> trial number to load. if isempty or not specifed, all the trials are loaded.
Returns
- Jinfo
- <<structure>> Information structure of loaded current. The fields are as below.
- .NJact
- The number of current vertices.
- .Ntrial
- The number of trials.
- .SampleFreq
- Sample Frequency [Hz].
- .Pretrigger
- Pretrigger period [sample].
- .Tmsec
- Time in msec.
- J
- Cortical current timecourse. [Jinfo.NJact x time]
vb_load_channel
Description
Loads channel position for plotting M/EEG data.
Remarks : difference between vb_load_channel and vb_load_sensor: In case of MEG, one channel is composed of multiple coils. vb_load_channel averages the coordinate values of the pair of coils and loads them as channel coordinates. For EEG, these two functions are almost synonymous.
syntax
[pos, channel_info] = vb_load_channel(meg_file, active_swt);
Parameters
- meg_file
- <<string>> VBMEG M/EEG file(.meg.mat/.eeg.mat)
- active_swt
- <<integer>> (optional)active switch
- 0
- return all the channels
- 1
- load only active channels [Default]
Returns
- pos
- Channel position [Nchannel x 3]
- channel_info
- <<structure>> loaded channel information.
- .Active
- Channel Active information(=0:Inactive, =1:Active).[Nchannel x 1]
- .Name
- channel name. {Nchannel x 1}
- .Type
- channel Type. [Nchannel x 1]
- .ID
- channel id. [Nchannel x 1]
vb_load_meg_data
Description
Loads M/EEG data.
Syntax
[data, channel_info, time_info] = vb_load_meg_data(meg_file, load_spec, new_file)
Parameters
- meg_file
- <<string>> VBMEG M/EEG file (.meg.mat/.eeg.mat)
- load_spec
- <<structure>> (optional) specification of loading data.
- .ChannelName
- target channel name list. [Nch x 1]
all the channels are specified. [Default]
e.g. {'1';'2';'3';'4'} - .ChannelSwitch
- <<boolean>> how to treat target channel.(.ChannelName)
- true
- Read target channel. [Default]
- false
- Read except for target channel.
- .ActiveChannel
- active channel filter switch.
- true
- load active channels [Default]
- false
- load all the channels.
- .ActiveTrial
- active trial filter switch.(valid only when data type is Evoked_Raw.)
- true
- load active trials. [Default]
- false
- load all the trials.
- new_file
- <<string>> (optional) Create a new M/EEG file from loaded M/EEG data according to load_spec.
Returns
- data
- M/EEG timeseries data. [Nchannel x Nsample x Ntrial]
- channel_info
- <<structure>> loaded channel information.
- .Active
- Channel Active info list. (=0:Inactive, =1:Active).[Nchannel x 1]
- .Name
- channel name. {Nchannel x 1}
- .Type
- channel type. [Nchannel x 1]
- .ID
- channel id. [Nchannel x 1]
- time_info
- <<structure>> time infomation of loaded data.
- .time
- time list in sec. [1 x Nsample]
- .sample_frequency
- sampling frequency of the data. [double]
Example
- Load active channels and trials.
data = vb_load_meg_data(meg_file);
- Load all channels including inactive channels and trials.
load_spec.ActiveChannel = false;
load_spec.ActiveTrial = false;
data = vb_load_meg_data(megfile, load_spec);
vb_load_sensor
Description
Loads sensor position. The main use is to load sensor position for computing leadfield.
Remarks : difference between vb_load_channel and vb_load_sensor: In case of MEG, one channel is composed of multiple coils. vb_load_channel averages the coordinate values of the pair of coils and loads them as channel coordinates. For EEG, these two functions are almost synonymous.
Syntax
[pick, Qpick, CoilWeight, Vcenter] = vb_load_sensor(meg_file);
Parameters
- meg_file
- <<string>> VBMEG M/EEG file(.meg.mat/.eeg.mat)
Returns
- pick
- n-th coil position. [Ncoil x 3]
- Qpick
- n-th coil direction.[Ncoil x 3]
- CoilWeight
- n-th coil weight for m-th channel. [Nchannel x Ncoil]
- Vcenter
- Center of spherical head model. [1x3]
vb_get_keyset_area
Description
Gets a list of keys for accessing area data stored in VBMEG Cortical area file(.area.mat).
Syntax
key_list = vb_get_keyset_area(area_file);
Parameters
- area_file
- <<string>>VBMEG Cortical area file(.area.mat)
Returns
- key_list
- <<cell string>> area name list.
vb_get_area
Description
Loads specified area data from VBMEG Cortical area file(.area.mat).
Syntax
area = vb_get_area(area_file, key);
Parameters
- area_file
- <<string>>VBMEG Cortical area file(.area.mat)
- key
- <<string>>key to load the area data(see vb_get_keyset_area).
Returns
- area
- <<structure>> area data.
- .Iextract
- <<vector>> Vertex index of cortical model V(see vb_load_cortex).
- .key
- <<string>> key of loaded area data.
vb_get_keyset_act
Description
Gets a list of keys for accessing activity data stored in VBMEG Cortical activity file(.act.mat).
Syntax
key_list = vb_get_keyset_act(act_file);
Parameters
- act_file
- <<string>>VBMEG Cortical activity file(.act.mat)
Returns
- key_list
- <<cell string>> area name list.
vb_get_act
Description
Loads specified activity data from VBMEG Cortical activity file(.act.mat).
Syntax
act = vb_get_area(act_file, key);
Parameters
- act_file
- <<string>>VBMEG Cortical activity file(.act.mat)
- key
- <<string>>key to load the act data(see vb_get_keyset_act).
Returns
- act
- <<structure>> activity data.
- .xxP
- <<vector>> Normalized activity of prior information(T-value). xxP (n) is prior to cortical model:V(n).(V:see vb_load_cortex). [Nvertex x 1]
- .key
- <<string>> key of loaded activity data.
.