Wt

Further to this question. If I set values in a Wt::WStandardItemModel like so, all is OK. I get axes and lines plotted:

        int row = 0;
        foreach_(const Y& d, map.keysY())
        {
            setData(row, 0, asWt(d)); // set x-axis column values
            int col = 1;
            foreach_(const std::string& key, map.keysX())
            {
                setData(row, col, map(key, d)); // set y values
                ++col;
            }
            ++row;
        }

If however I try the following, I get axes with labels that do not represent the data, and no lines plotted:

        Wt::WStandardItem* root = invisibleRootItem();
        std::vector<Wt::WStandardItem*> xs;

        foreach_(const Y& d, map.keysY())
        {
            Wt::WStandardItem* xVal = new Wt::WStandardItem();

            xVal->setData(asWt(d)); // set x-axis column values

            xs.push_back(xVal);
        }
        root->appendColumn(xs);

        foreach_ (const std::string& key, map.keysX())
        {
            std::vector<Wt::WStandardItem*> ys;

            foreach_(const Y& d, map.keysY())
            {
                Wt::WStandardItem* yVal = new Wt::WStandardItem();

                yVal->setData(map(key, d)); // set y values

                ys.push_back(yVal);
            }
            root->appendColumn(ys);
        }

Otherwise code is the same. It looks like I am structuring the data incorrectly, but don't know how to do it correctly!

Thanks for any advice.

John

Hey John,

To have different X-axis for each series (for scatter plots only!), you need to use WDataSeries::setXSeriesColumn() to provide a different X column for each series.

As to your second question, you need to use:

  yVal->setData(v, Wt::DisplayRole)

Regards,

koen

Hi Koen

Thanks - that worked a treat!

John

Further to the above - how do I access the column vectors - I don't see anywhere in the API to do this.

I have tried the following, but the cast always fails.

for (int col = 0; col < columnCount(); ++col)

{

for (int row = 0; row < rowCount(); ++row)

{

Wt::WStandardItem* x = invisibleRootItem()->child(row, col);

if (x)

{

const boost::any any = x->data(Wt::DisplayRole);

typedef Wt::WDate WT;

if (boost::any_cast<const WT*>(&any)) // cast always fails

{

WT w = boost::any_cast(any);

// etc

}

}

}

}

I assume there is a simple way of getting at the data! Any advice would be appreciated.

John

Mea culpa.

Should be:

boost::any_cast<const WT>(&any))

Hey,

Note that any_cast is pedantic: the type has to be an exact match. A const versus non-const type is different, for example.

If you put in a WDate, then you should be able to get back a WDate (but not a const WDate).

Regards,

koen

Yes, but boost::any_cast has:

T boost::any_cast(boost::any);

and

T* boost::any_cast(boost::any*);

I mistakenly assumed (which would be more logical) that the latter prototype was:

T* boost::any_cast<T*>(boost::any*);

Just one of those little vagaries!

Cheers

John