I am passing in a variable name MetabMapString to the function spectroscopy(). MetabMapString is the name of the field I want to call. But It seems as if Matlab is thiking that MetabMapString is the name of the fields cause it returns that there is no field names MetabMapString. I have included some code. Is there a way to get this to work?
function spectroscopy(MetabMapString)
spect = importdata(spectLCMI);
n = length(spect.MetabMapString);
Row = spect.Row;
Col = spect.Col;
spectOrig = spect.MetabMapString;
...
end
Here is the error
??? Reference to non-existent field 'MetabMapString'.
Error in ==> SpectDraw>spectroscopy at 1165
n = length(spect.MetabMapString);
It should be:
n = length(spect.(MetabMapString));
That should work. Same in all other places where you're using a variable which contains a string as a field name of a struct or MATLAB class, or as a method name of a class:
spectOrig = spect.(MetabMapString);
Related
This question already has answers here:
Access struct field by variable
(3 answers)
Closed last month.
I am new to rust with a javaScript background and i am stuck with getting a value of a json key dynamically.
In JS if i have an object = { "xyz" : "one" , "jkl" : "two" }; and if i have a variable name = "xyz"; , then i can find the corresponding value of 'xyz' key in the object using object[name] which will give me "one" as a result.
Now i have the exact same flow in rust, where i have
let obj = config.clone(); // because config is struct (only cloning could remove the error)
let name = "xyz"; // A variable which is a key in the object
let result = obj[name];` // result which is giving me "cannot index into a value of type `Configuration`" error
I am aware that creating a dict or hashmap will exponentially reduce the time, but the object i have can contain upto 1000 keys and values or more.
If i can create a hashmap with the object I already have, that would be a relief ( only if i knew ).
I have tried multiple ways by just googling a bunch of stuff
let result = obj[name];
let result = obj.&name];
let result = obj[$name];
let result = obj[&name];
let result = obj.$name;
none of them seems to solve the issue.
Thanks in advance.
Accessing fields of structs dynamically is not possible out of the box. See this earlier question.
In my example, I am creating a class Person and setting a default value for the member "Name".
I have a constructor, and a function called sayHi(). Whenever I try to call that function I get an error:
lua: test.lua:22: attempt to call a nil value (method 'sayHi')
stack traceback:
test.lua:22: in main chunk
[C]: in ?
So from what I understand I am creating a new table, setting the table's metatable (setmetatable) to the Person class, and then returning that table, which means I should be able to use its sayHi() function, but I am getting a nil value.
Person = {}
Person.Name = "No name inputted"
function Person:new(name)
local o = {}
setmetatable(o,self)
self._index = self
return o
end
function Person:sayHi()
print(self.Name .. " says hi")
end
firstPerson = Person:new("Michael")
secondPerson = Person:new("Julian")
print(firstPerson.Name)
secondPerson:sayHi()
The correct property name on metatables is __index (two leading underscores). You're assigning to _index (one leading underscore).
I am creating a table in a function, so the function outputs a table to the assigned variable name as shown below
[name] = tablefunc(input1, input2)
The thing is I want to be able to have the name be an input that was assigned earlier for example
name = 'dogs'
[something] = tablefunc(input1,input2)
I want to be able to put some code where it says something so that the outputted table for tablefunc is assigned the variable name dogs
It might be confusing why I am doing this but it is because I am extracting tables from a txt file in a for loop so I am getting lots of tables generated and I want to be able to give the tables their appropriate names as opposed to just table1, table2 etc.
That's not a good idea. As an alternative, you should create a structure:
function t = tablefunc(input1,input2)
t = table(input1,input2);
end
name = 'dogs';
s = struct();
s.(name) = tablefunc(rand(2),rand(2));
You can have one field per txt file.
I've got a small code snippet that loops through a node and grabs all its properties.
I can get this to work if I set one variable to grab the properties values (except it has a weird [] surrounding it). But I don't want redundant code so I'm trying to set multiple properties inside the loop, except all that returns is a single value, it's not looping around all the nodes.
WORKING
String selectNodeLabel = null
selectNodeLabel = JcrUtils.getChildNodes("links").collect{
it.getProperty("label").getString()
}
SINGLE VALUE
String selectNodeLabel = null
String selectNodeMeta = null
String selectNodeFooter= null
String topicNode = null
topicNode = JcrUtils.getChildNodes("links").collect{
selectNodeLabel = it.getProperty("label").getString()
selectNodeMeta = it.getProperty("meta").getString()
selectNodeFooter = it.getProperty("footer").getString()
}
Thanks for any help!
Try:
def nodeList = JcrUtils.getChildNodes("links").collect{
[ selectNodeLabel : it.getProperty("label").getString()
selectNodeMeta : it.getProperty("meta").getString()
selectNodeFooter : it.getProperty("footer").getString() ]
}
Then, nodeList will be a list of Maps, so you could do:
println nodeList*.selectNodeLabel
To print all the selectNodeLabel values for example.
To explain the problems with your code... Collect creates a list of the elements returned by the closure. What your SINGLE VALUE code is doing is overwriting the values in the selectNode... variables, and then setting topicNode to the value returned from the closure for each element in JcrUtils.getChildNodes("links").
For this case, topicNode will contain a List of it.getProperty("footer").getString() (as it is the last line in the Closure
I have been tasked with modifying some legacy ActiveX DLLs written in Visual Basic 6. One of the things I need to do is to emulate the "ScriptingContext" object, (so that we can support other mechanisms for running the DLLs other than IIS without having to re-write large chunks of the code).
Something that has been causing me some grief is the "ASPTypeLibrary.Application" object which has two very different ways to access its stored values, eg:
.Application("KeyName")
or
.Application.Value("KeyName")
How can I create my own VB6 class which supports both of these access mechanisms? I can do one or the other but not both?
(a simple code example would be great thanks, I'm not a VB6 programmer)
I have found a way to do this, see the code snippet below taken from two classes, "clsContext" and "clsContextApp". The latter implements the ".Value" functionality and the former has the ".Application" property...
I have now discovered an even more difficult problem. The ScriptingContext's "ASPTypeLibrary.Request" object has three different ways to access its ".Request.QueryString" property:
.Request.QueryString("KeyName")
or
.Request.QueryString.Value("KeyName")
or
.Request.QueryString
The last method returns a string comprised of all the Key/Value pairs concatenated by "&" characters. I have no idea how to implement this?
' clsContext
Public ContextApp As clsContextApp
Public Property Get Application(Optional ByRef Key As Variant = Nothing) As Variant
If (Key Is Nothing) Then
Set Application = ContextApp
Else
If (Not ContextApp.p_Application.Exists(Key)) Then
Application = ""
Else
Application = ContextApp.p_Application.Item(Key)
End If
End If
End Property
Public Property Let Application(ByRef Key As Variant, ByVal Value As Variant)
If (VarType(Key) = vbString) Then
If (VarType(Value) = vbString) Then
If (Not ContextApp.p_Application.Exists(Key)) Then
ContextApp.p_Application.Add Key, Value
Else
ContextApp.p_Application.Item(Key) = Value
End If
End If
End If
End Property
' clContextApp
Public p_Application As Scripting.Dictionary
Public Property Get Value(Key As String) As String
If (Not p_Application.Exists(Key)) Then
Value = ""
Else
Value = p_Application.Item(Key)
End If
End Property
Public Property Let Value(Key As String, Value As String)
If (Not p_Application.Exists(Key)) Then
p_Application.Add Key, Value
Else
p_Application.Item(Key) = Value
End If
End Property
Well I've managed to answer the additional question regarding ScriptingContext's "ASPTypeLibrary.Request" object which has three different ways to access its ".Request.QueryString" property.
I've included a code snippet below that is based on the code from my previous answer for the "ASPTypeLibrary.Application" object. If I add a new Property to the "clsContextApp" class and make it the default property for that class, then it will be called when the ".Application" property is called without any qualification eg:
MyString = Context.Application
Setting a particular property as the default property in VB6 is a little obscure, but I followed the directions I found here.
' clsContextApp Default Property
Property Get Values(Optional ByVal Index As Integer = -1) As String ' This is the Default Value for clsContextApp
Attribute Values.VB_UserMemId = 0
Dim KeyName As String, Value As String
Values = ""
If (Index < 0) Then
For Index = 0 To p_Application.Count - 1
KeyName = p_Application.Keys(Index)
Value = p_Application.Item(KeyName)
If (Index > 1) Then
Values = Values + "&"
End If
Values = Values + KeyName + "=" + Value
Next Index
Else
If (Index < p_Application.Count) Then
KeyName = p_Application.Keys(Index)
Value = p_Application.Item(KeyName)
Values = KeyName + "=" + Value
End If
End If
End Property
Adding a reference to Microsoft Active Server Pages Object Library, and to COM+ Services Type Library, and then using the object browser reveals some basic things you seem to be missing.
GetObjectContext is a global method in COMSVCSLib with no arguments used to retrieve the current ObjectContext as its return value.
ObjectContext is a Class. It has a read-only default property, named Item that takes a String argument and is of type Variant.
Passing "Application" as an argument to Item returns the current instance of the Application Class.
ScriptingContext is a Class. It is obsolete.
Application is another Class. It has a default property named Value that takes a String argument and is of type Variant.
Value is a property of the Application Class and provides access to a read-write key/value pair store where keys are always Strings. Since it is of type Variant you can store objects as well as simple values and arrays of various types.
None of this looks difficult to replicate in VB6. The key/value store could be a Collection or Scripting.Dictionary.