class of property Solution.Mode is not double as with COM-Interface

Hi Paulo. It is Janis again. (We're aso talking in the DSS Discussion Forum.)

I had just this small error switching from COM to altDSS. I think it is easy to fix.

After this here is some - hopefully excecutably - code which should print

```
=== DSS Interface: COM ===

original Solution properties: Mode = 0 ModeID = Snap
class for Solve Mode = double

Trying to set ModeID to
Error setting Mode ID
Invoke Error: Incorrect number of arguments

Error in Issue_Solution_Mode_difference (line 57)
Solution_I.ModeID = ModeID;
Solution properties: Mode = 0 ModeID = Snap

Trying to set Mode to <2>
Solution properties: Mode = 2 ModeID = Yearly

Trying to set original solve Mode <0>
Solution properties: Mode = 0 ModeID = Snap

=== DSS Interface: altDSS ===

original Solution properties: Mode = 0 ModeID = Snap
class for Solve Mode = DSS_MATLAB.SolveModes

Trying to set ModeID to
Solution properties: Mode = 0 ModeID = Snap

Trying to set Mode to <2>
Solution properties: Mode = 2 ModeID = Yearly

Trying to set original solve Mode <0>
Error using calllib
Array must be numeric or logical.

Error in DSS_MATLAB.ISolution/set.Mode (line 434)
calllib(obj.libname, 'ctx_Solution_Set_Mode', obj.dssctx, Value);

Error in Issue_Solution_Mode_difference (line 81)
Solution_I.Mode = Mode_original;
Solution properties: Mode = 2 ModeID = Yearly

Trying to set original solve Mode <0> with type conversion to double
Solution properties: Mode = 0 ModeID = Snap
```

```matlab
commands = {
'Clear'
'set defaultbasefreq=50' % 50 Hz
'New Circuit.ckt Angle=0 Mvasc3=1e7 basekv=0.4 bus1=n1 frequency=50 phases=3 pu=1.0 x1r1=10'
'New Linecode.nayy4x120 C0=365.9 C1=797.3 R0=1.02 R1=0.255 X0=0.292 X1=0.08 NormAmps=245.0 units=km'
'New Line.l1 bus1=n1 bus2=n2 length=0.3 linecode=nayy4x120'
'solve mode=snap'
'solve algorithm=newton'
'Set Maxiter=75'
};

for phase = 1:3
commands{end+1} = sprintf('New Load.rl_1_ph%1$d bus1=n2.%1$d phases=1 kv=0.4 kW=0 kvar=0', phase); %#ok
end

for interface = {'COM', 'altDSS'}

current_dir = pwd;
switch interface{1}
case 'COM'
DSS_I = actxserver('OpenDSSEngine.DSS');
case 'altDSS'
DSS_I = DSS_MATLAB.IDSS;
end
cd(current_dir)
fprintf(1, '\n\n=== DSS Interface: %s ===\n\n', interface{1})

Text_I = DSS_I.Text;
Circuit_I = DSS_I.ActiveCircuit;
Solution_I = Circuit_I.Solution;

for c = reshape2rowVec(commands)
Text_I.Command = c{1};
end

Text_I.command = 'set voltagebases=0.4';
Text_I.command = 'calcvoltagebases';
Solution_I.Solve;

fprintf(1, 'original Solution properties: Mode = %d ModeID = %s\n', Solution_I.Mode, Solution_I.ModeID)

Mode_original = Solution_I.Mode;

fprintf(1, 'class for Solve Mode = %s\n', class(Mode_original))

%%

ModeID = 'yearly';

fprintf(1, '\nTrying to set ModeID to <%s>\n', ModeID)

try
Solution_I.ModeID = ModeID;
catch err
fprintf(2, 'Error setting Mode ID\n%s\n', err.getReport)
end

fprintf(1, 'Solution properties: Mode = %d ModeID = %s\n', Solution_I.Mode, Solution_I.ModeID)

%%
Mode = 2;

fprintf(1, '\nTrying to set Mode to <%d>\n', Mode)

try
Solution_I.Mode = Mode;
catch err
fprintf(2, '%s\n', err.getReport)
end

fprintf(1, 'Solution properties: Mode = %d ModeID = %s\n', Solution_I.Mode, Solution_I.ModeID)

%%
fprintf(1, '\nTrying to set original solve Mode <%d>\n', Mode_original)

try
Solution_I.Mode = Mode_original;
catch err
fprintf(2, '%s\n', err.getReport)
fprintf(1, 'Solution properties: Mode = %d ModeID = %s\n', Solution_I.Mode, Solution_I.ModeID)

fprintf(1, '\nTrying to set original solve Mode <%d> with type conversion to double\n', Mode_original)

Solution_I.Mode = double(Mode_original);

end

fprintf(1, 'Solution properties: Mode = %d ModeID = %s\n', Solution_I.Mode, Solution_I.ModeID)

end

```

I experienced these 2 differences.

### 1

With COM numerical Solution ModeID is read-only. It errors when trying to set. with DSS_Matlab setting is possible without error but it does not set it. I would suggest to make the property in `ISolution.m` read-only by:

``` matlab
properties (SetAccess = private)
ModeID
end
```

### 2
Solution_I.Mode returns double with COM.

Solution_I.Mode returns enumeration or sth with DSS_Matlab.

When trying to set Mode again with this datatype there is an error.

That could be fixed in the `ISolution.m` class itself by casting to double:

``` matlab
function result = get.Mode(obj)
% Set present solution mode (by a text code - see DSS Help)
result = double(DSS_MATLAB.SolveModes(calllib(obj.libname, 'ctx_Solution_Get_Mode', obj.dssctx)));
obj.CheckForError();
end
```